### Interesting Number

This interesting number is **66**.

**66** is a **triangular** number.

1, 3, 6, 10, 15 ,21, 28, 36, 45, 55, **66**

The factors of **66** are 1, 2, 3, 6, 11, 22, 33 and **66**.

**66** in Roman numerals is expressed as LXVI.

**66** is 1000010 in binary.

**66** is the atomic number of dysprosium, a landthanide

**66** is the international dialling code of Thailand.

Route **66**, a famous highway in the USA.

19**66** was the last and only time England won the football World Cup

### Interesting Number

This interesting number is **56**.

**56** is the sum of the first six **triangular** numbers.

1 + 3 + 6 + 10 + 15 + 21

**56** is the sum of the six **prime** numbers.

3 + 5 + 7 + 11 + 13 + 17

The factors of **56** are 1, 2, 4, 7, 8, 14, 28 and **56**.

**56** in Roman numerals is expressed as LVI.

**56** is 111 000 in binary.

**56** spectators died in the **Bradford City** football stadium fire on 11 May 1985.

**56** is the atomic number of **Barium**.

**56** is the international dialling code of Chile.

**Shirley Temple** (US child actress) had **56** curls in her hair.

**56** men signed the US** Declaration of Independence** in 1776.

**Steve Jobs** died aged **56**.

### Interesting Number

This interesting number is **54**.

**54** is a Leyland number. **54** can be written as the sum of three squares in three different ways:

7^{2} + 2^{2} + 1^{2} = 6^{2} + 3^{2} + 3^{2} = 5^{2} + 5^{2} + 2^{2} = **54**.

It is the smallest number with this property.

The factors of **54** are 1, 2, 3, 6, 9, 18, 27 and **54**.

There are **54** countries in Africa.

**54** in Roman numerals is expressed as LIV.

**54** is 110110 in binary.

**54** is the atomic number of **Xenon**.

A score of **54** in golf is colloquially referred to as a perfect round.

This score has never been achieved in competition.

**54** is the international dialling code of Argentina.

### Interesting Number

This interesting number is **38**.

**38** is the sum of the squares of the first three primes.

**38** is the largest even number that cannot be written as the sum of two odd composite numbers.

The factors of **38** are 1, 2, 19 and **38**

**38** in Roman numerals is expressed as XXXVIII

**38** is 100110 in binary.

**38** is the atomic number of **Strontium**.

**38** is the number of games of football played by each team, each season in the EPL (English Premier League) and La Liga (Spain).

**38** is the number of slots on an American roulette wheel. (1 to 36, 0, 00)

### Interesting Number

This interesting number is **45**.

**45** is a triangular number, and in particular the sum of all the decimal digits

(0 + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = **45**)

The factors of **45** are 1, 3, 5, 9, 15 and **45**

**45** in Roman numerals is expressed as XLV

**45** is 101101 in binary.

**45** is the atomic number of **Rhodium**.

There are **45** degrees in half of a right angle.

+**45** is the telephone dialing code for Denmark.

A football game consists of two halves of **45** minutes each.

World War Two ended in 19**45**.

### Interesting Number

This interesting number is **59**.

**59** is the 17th prime number.

The factors of **59** are 1 and **59**

**59** in Roman numerals is expressed as LIX

**59** is 111011 in binary.

**59** is the atomic number of **Praseodymium**.

A **59** sided polygon is called a nonogon

Beethoven’s Opus**59** consists of the three so-called Razumovsky Quartets

The 1960s song **“59 ^{th}" Street Bridge Song (Feelin’ Groovy)”** was a big hit for

**Simon and Garfunkel**

**59** is apporoximately the number of days in 2 lunar months.

In the USA the Interstate **59** runs between Minnesota and Texas.

**59** is the lowest recorded golf score on the womens’ LPGA tour by **Annika Sorenstam**.

### Interesting Number

This interesting number is **9**.

**9** is a composite number.

The factors of **9** are 1, 3 and **9**

**9** is a perfect square (32).

**9** in Roman numerals is expressed as IX

**9** is 1001 in binary.

**9** is the atomic number of Flourine.

A **9** sided polygon is called a nonogon

### Interesting Number

This interesting number is **27**.

The factors of **27** are 1, 3, 9, and **27**

**27** is a perfect cube (33).

**27** in Roman numerals is expressed as XXVII.

**27** is 11011 in binary.

**27** is the atomic number of Cobalt.

**27** is the only positive integer that is three times the sum of its digits.

Dark matter is thought to make up **27**% of the universe.

**27** is the number of letters in the Spanish alphabet.

### Interesting Number

This interesting number is **30**.

The factors of **30** are 1, 2, 3, 5, 6, 10, 15 and **30**

**30** is the number of tracks on the Beatles’ famous **The White Album**.

**30** in Roman numerals is expressed as XXX.

**30** is 11110 in binary.

**30** is the atomic number of Zinc

The Platonic solids, the **dodecahedron** and the **icosahedron** both have **30** faces

**30** years of marriage is called the **pearl** anniversary.

### Interesting Number

This interesting number is **41**.

The factors of **41** are 1 and **41**

**41** is the 13^{th} smallest prime number.

**41** is the sum of the first six prime numbers.

**41** is the sum of two squares 16 and 25.

**41** in Roman numerals is expressed as XL1.

**41** is 101001 in binary.

**41** is the atomic number of Niobium

Symphony **41** is the longest and last symphony of Wolfgang Amadeus Mozart.

**41** was The race number worn by Sir Roger Bannister when he broke the mythical 4-minute mile barrier in 1954.

George H W Bush was the **41**^{st} President of the United States

### Interesting Number

This interesting number is **111**.

The factors of **111** are 1, 3, 37 and **111**

**111** in Roman numerals is expressed as CX1.

**111** is 1101111 in binary.

**111** is the atomic number of Roentgenium (rg).

The emergency telephone number in New Zealand is **111**.

A score of **111** in cricket or multiples thereof (222 = "double nelson", 333 = "triple nelson" and so on) is considered unlucky by some in English cricket: most famously by the international umpire David Shepherd who had a whole retinue of peculiar mannerisms - hops, shuffles, jiggles and so on - that he would indulge in if the score was ever a "Nelson" multiple.

Particularly if the number of wickets also matched - **111**/1, 222/2 etc.

Occasionally **111** is referred to as "eleventy- one", as read in The Fellowship of the Ring by J.R.R. Tolkien

**111** is the lowest positive integer requiring six syllables to name in American English, or seven syllables (including "and") in Canadian and British English.

### Interesting Number

This interesting number is **75**.

The factors of **75** are 1, 3, 5, 15, 25 and **75**.

52 in Roman numerals is expressed as LXXV.

52 is 1001011 in binary.

52 is the atomic number of **rhenium**.

The age limit for Canadian senators is **75**.

### Interesting Number

This interesting number is **52**.

The factors of **52** are 1, 2, 4, 13, 26 and **52**.

**52** in Roman numerals is expressed as LII.

**52** is 110100 in binary.

**52** is the atomic number of **tellurium**.

A year has approximately **52** weeks.

On a piano there are **52** white keys.

**52** is the international direct dial code for Mexico.

There are **52** cards in a standard pack of playing cards.

### Interesting Number

This interesting number is **29**

**29** is the tenth prime number

The factors of **29** are 1 and **29**.

**29** in Roman numerals is expressed as XXIX.

**29** is 11101 in binary.

**29** is the atomic number of **copper**.

None of the first **29** natural numbers have more than two different prime factors.

This is the longest such consecutive sequence.

India has **29** states.

**29** Palms is the name of a town in California, in the USA.

The Lunar month is close to **29** days.

### Interesting Number

This interesting number is **90**

The factors of **90** are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and **90**.

**90** in Roman numerals is expressed as XC

**90** is 1011010 in binary.

**90** is the atomic number of **thorium**.

**90** is the direct dial number for Turkey.

**90** is the latitude in degrees of the North and South poles.

There are **90** minutes in a football match.

### Interesting Number

This interesting number is **92**.

The factors of **92** are 1 and **92**.

**92** is a **pentagonal** number

**92** in Roman numerals is expressed as XC11

**92** is 1011100 in binary.

**92** is the atomic number of **uranium**.

**92** is the direct dial number for Pakistan.

**92** letters in the longest place name in the world in New Zealand:

**Taumatawhakatangihangakoauauotamateaurehaeaturipukakapikimaungahoronukupok**

The **92** Club is a society of UK football fans who have attended a home match of all **92** current member clubs of the Premier League and The Football League in England and Wales.

### Interesting Number

This interesting number is **73**

The factors of **73** are 1 and **73**.

**73** is the 21^{st} prime number.

**73** in Roman numerals is expressed as LXXIII.

**73** is 1001001 in binary.

**73** is the atomic number of **tantalum**.

**73** is the number of seconds it took for the Space Shuttle Challenger shuttle to explode.

### Interesting Number

This interesting number is **16**.

The factors of **16** are 1, 2, 4, 8 and **16**.

**16** is the fourth power of 2.

**16** in Roman numerals is expressed as XVI.

**16** is 10000 in binary.

**16** is the atomic number of **sulphur**.

### Interesting Number

This interesting number is **44**

The factors of **44** are 1, 2, 4, 11, 22 and **44**

**44** is a composite number

**44** in Roman numerals is expressed as XLIV

**44** is 101100 in binary

**44** is the atomic number of **ruthenium**

**44** is a palindromic number and also a “happy” number.

**44** is the driver number of Lewis Hamilton , the Formula One racing car driver.

**44** is the direct dialing code for the United Kingdom.

Route **44** is the Interstate Highway in the US that runs from Texas to Missouri.

**44** fours is the name of a song by Jay Z where he rhymes the words four, for and fore **44** times.

Vicks Formula **44** is a popular cough medicine.

Barack Obama is the **44**th President of the United States.

### Interesting Number

This interesting number is **22**

The factors of **22** are 1, 2, 11 and **22**

**22** is a composite number

**22** in Roman numerals is expressed as XXII

**22** is 10110 in binary

**22** is the atomic number of **titanium**

**22****/7** is used as an approximation for the irrational number π

The **22** is an important line on a rugby field, **22** metres from each try-line

In Australian Rules football, each squad is allowed **22** players

**22** yards is the length of a cricket pitch

Taylor Swift has a song on her fourth album **Red** called **22**

Catch **22** is a famous novel by Joseph Heller

There are **22** **yards** in a **chain**

There are **22** players on the field at any one time in a soccer game and an American football game..

### Interesting Number

This interesting number is **51**

The factors of **51** are 1, 3, 17 and **51**

**51** is a composite number

**51** in Roman numerals is expressed as LI

**51** is 110011 in binary

**51** is the atomic number of **antimony**

**51** is the direct dial code for **Peru**

**51** is the title of a 2011 Horror movie

**51**^{st} State is the name given to any future state of the US

**51** is the name of an episode of the TV series **Breaking Bad**

### Interesting Number

This interesting number is **67**.

The factors of **67** are 1 and **67**.

**67** is the 19^{th} prime number.

**67** in Roman numerals is expressed as LXVII

**67** is 1000011 in binary.

**67** is the atomic number of **holmium**, a lanthanide.

Two songs are, “**Questions 67 and 68**” by the band Chicago and “**Old 67**” by Elton John

**67** is the highest two digit number presently NOT designating a highway in the US.

**67** is the number of throws in Judo

### Interesting Number

This interesting number is **79**.

The factors of **79** are 1 and **79**

**79** is the 22^{nd} prime number

**79** in Roman numerals is expressed as LXXIX

**79** is 1001111 in binary.

**79** is the atomic number of **gold (Au)**.

**79** is the record number of cumulative weeks at Number 1 on the music charts held by Elvis Presley

### Interesting Number

This interesting number is **85**.

The factors of **85** are 1, 5, 17 and **85**

The prime factors are 5 x 17

**85** in Roman numerals is expressed as LXXXV

**85** is 1010101 in binary.

**85** is the atomic weight of **astatine**

**85** is a **biprime**, the product of two prime numbers 5 and 17.

**85** along with 86 and 87 is the second cluster of consecutive biprimes.

In base 2, **85** is a palindrome (1010101)

**85** is a centred triangular number.

### Interesting Number

This interesting number is **63**.

The factors of **63** are 1, 3, ,7, 9, 21 and **63**

The prime factors are 3^{2} x 7

**63** in Roman numerals is expressed as LXIII

**63** is 111111 in binary.

**63** is the atomic weight of **europium**.

**63** is the smallest whole number that can be divided by any number from 1 to 9 without repeating decimals.

The Philippines has 0**63** as its international dialling code.

There are **63** chromosomes in a donkey **and** a horse.

### Interesting Number

This interesting number is **28**.

The factors of **28** are 1, 2, 4,7, 14 and **28**

**28** in Roman numerals is expressed as XXVIII

**28** is 11100 in binary.

**28** is the atomic weight of **silicon**.

There are **28** countries in the European Union (June 2015). **Croatia** being the latest.

No country has 0**28** as its international dialing code.

There are **28** dominoes in a standard set of dominoes.

**28** is the sum of the first 5 prime numbers.

**28** is the number of days in the shortest month of the year (except in Leap years).

**28** was the number of sports at the Sydney (2000) Olympics.

The normal number of human teeth (excluding wisdom) is **28**.

It takes **28** Earth years for Saturn to revolve around the Sun.

### Interesting Number

This interesting number is **70**.

The factors of **70** are 1, 2, 5, 7, 10, 14, 35 and **70**

**70** in Roman numerals is expressed as LXX

**70** is 1000110 in binary.

**70**^{2} is the sum of the first 24 square numbers starting at 1.

The Old Testament of the Bible allots three score and ten (**70** years) for a man's life.

In Olympic Archery, the targets are **70** metres from the archers.

**70** is the atomic number of **ytterbium**, a lanthanide.

### Interesting Number

This interesting number is **37**.

The factors of **37** are 1 and **37**

**37** in Roman numerals is expressed as XXXVII

**37** is 100101 in binary.

**37** is the 12^{th} **Prime** number

**37** and **38** are the first pair of consecutive positive integers that are not divisible by any of their digits.

**37** is the normal human body temperature in degrees Celsius.

William Shakespeare is thought to have written **37** plays (counting Henry IV as three parts).

In gambling, there are **37** numbers on a roulette wheel (0 – 36).

There are 10 international dialing codes that begin with the digits **37**.

**37** is the number people choose most often when asked to give a number between 1 and 100.

### Interesting Number (30 November 2015)

This interesting number is **11**.

The factors of **11** are 1 and 11.

**11** in Roman numerals is expressed as XI.

**11** is 10**11** in binary.

**11** is the 5^{th} **Prime** number.

An **11**-sided polygon is called a **hendecagon** or **undecagon**.

Apollo **11** was the first manned spacecraft to land on the Moon.

There are **11** players in soccer and field hockey teams.

In American football there are **11** players on the field at any on time.

If a number is divisible by **11**, reversing its digits will result in another multiple of **11**.

World War One ended on with an Armistice in November, 1918. It went into effect at **11**am on the **11**^{th} day of the **11**^{th} month.

The maple leaf on the flag of Canada has **11** points.

### Interesting Number

This interesting number is **53**.

The factors of **53** are 1 and **53**.

**53** in Roman numerals is expressed as LIII

**53** is 110101 in binary.

**53** is the 16^{th} **Prime** number.

**53** is the atomic number of iodine.

**53** is the international direct dial number for phone calls to Cuba.

**53** was the racing number of **Herbie**, the VW Beetle from the 1969 movie, **The Love Bug**.

**53** was the record number of field goals scored by **Michael Jordan**, in a three-game series in the NBA Basket ball play-offs, in 1992.

### Interesting Number

This interesting number is **99**.

The factors of **99** are 1, 3, 9, 11, 33, 99.

**99** in Roman numerals is expressed as XCIX

The prime factors of **99** are 3 x 3 x 11

**99** is 1100011 in binary.

**99** is the sum of the cubes of three consecutive whole numbers 2^{3} + 3^{3} + 4^{3}

**99** is a **palindromic** number.

**99** is the atomic number of Einsteinium. It was discovered in 1952 in the debris of the first H-bomb explosion and named after Albert Einstein.

The earliest known reference to a **99**-flake ice-cream with a chocolate flake was in 1935. One idea links it to a shop in Scotland at **99** Portobello High St which added chocolate flakes to its ice-creams.

“If you wish to live to the age of **99**, please walk. 100 steps after each meal,” (Chinese proverb).

### Interesting Number

This interesting number is **14**.

The factors of **14** are 1, 2, 7, **14**.

**14** in Roman numerals is expressed as XIV

The prime factors of **14** are 2 x 7

**14** is 1110 in binary.

**14** is the sum of the first three square numbers making it a **square pyramidal number**.

There are **14** pounds in a stone. (British weight measurements before metrics)

The atomic number of **Silicon** is **14**.

**14** is the number of days in a **fortnight**.

The Top **14** is the highest-level rugby competition in France.

**14** – the shirt number worn by Johan Cruyff, the Dutch footballer. No longer used by his former club Ajax.

There are **14** lines in a **sonnet**.

February **14** – St Valentine’s Day

### Interesting Number

This interesting number is **95**.

The factors of **95** are 1, 5, 19, **95**.

**95** in Roman numerals is expressed as XCV

The prime factors of **95** are 5 x 19

**95** is 1011111 in binary.

In statistics a **95** % confidence interval is considered satisfactory for most purposes.

**Hit** **95** **FM**- A popular Indian radio station.

The atomic number of **Americium** is **95**.

United States Interstate **95**, a freeway that runs from Florida to Maine.

Windows **95** A popular computer operating system.

**95** – a good mark and a good age!

### Interesting Number

This interesting number is **25**.

The factors of **25** are 1, 5, **25**.

**25** in Roman numerals is expressed as XXV

The prime factors of **25** are 5 x 5 or 5^{2}

**25** is 11001 in binary.

**25** is the smallest square that is also the sum of two non-zero squares (**25** = 3^{2} + 4^{2})

**25** is a square number 5^{2} = **25**

**25** years of marriage is marked by a **SILVER** wedding anniversary.

The atomic number of **Manganese** is **25**.

**The M** **25** is a motorway around London.

United States Interstate **25**, a freeway that runs from New Mexico to Wyoming.

### Interesting Number

This interesting number is **57**.

The factors of **57** are 1, 3, 19 and **57**.

**57** in Roman numerals is expressed as LVII.

The prime factors of **57** are 3 x 19.

**57** is 111001 in binary.

**57** is the number of varieties of foods claimed to be produced by the H.J. Heinz Company.

The code of international dialling calls to **Columbia** is **57**

The atomic number of **Lanthanum** is **57**.

**Interstate** **57** is a freeway in the USA that runs from Missouri to Chicago.

### Interesting Number

This interesting number is ** 26**.

The factors of **26** are 1, 2, 13, and **26**.

**26** in Roman numerals is expressed as XXVI

The prime factors of **26** are 2 x 13.

**26** is 11010 in binary.

The atomic number of Iron is **26**.

A rhombicuboctahedron has **26** faces.

When 27 small cubes are made into a larger 3x3x3 cube, **26** of them can be seen on the outside of the larger cube.

There are **26** miles, rounded, in a marathon running race.

**26** is the "joke throw" in the game of darts, where a player throws 20, 5 and 1 when aiming for 20 (or treble 20). In professional darts, throwing **26** usually results in sneers or laughter from the audience.

**26** is the number of bones in the normal human **foot** and **ankle**.

**26** is the number of letters in the English alphabet.

There are **26** red cards and **26** black cards in a normal deck of cards.

**26** is the only number that is 1 more than a square number (**25** = 5^{2}) AND 1 less than a cube (**27** = 3^{3})

### Interesting Number

This interesting number is **19**.

**19** is the 8th prime number.

**19** in Roman numerals is expressed as XIX.

**19** is 10011 in binary.

**19** is a **centred** triangle number.

The atomic number of **Potassium** is **19**.

The game of GO, is usually played on a grid of **19** X **19**.

**19** (or 18) is often the minimum age for buying alcohol and tobacco in many places around the world.

### Interesting Number

This interesting number is **77**.

**77** is the sum of the first eight prime numbers.

i.e. 2 + 3 + 5 + 7 + 11 + 13 + 17 + 19

**77** is the sum of the squares of three consecutive whole numbers.

i.e. 4^{2} + 5^{2} + 6^{2}

The prime factors of **77** are 7 and 11.

**77** in Roman numerals is expressed as LXXVII.

**77** is 1001101 in binary.

**77** Sunset strip was a popular TV programme in the 1950’s-1960’s

The atomic number of **iridium** is **77**.

**77** is the boiling point of nitrogen (in degrees Kelvin), that is equal to –195.79^{o}C.

**77** is the only whole number under 100 which when spoken has 5 syllables.

### Interesting Number

This interesting number is **33**.

**33** is the smallest sum of two different positive numbers each of which raised to the fifth power: 1^{5} + 2^{5}

**33** is the largest positive integer that cannot be expressed as the sum of different triangle numbers.

The prime factors of **33** are 3 and 11.

In **Roman** Numerals the number **33** can be written as **XXXIII**.

**33** is **100001** in binary.

The atomic number of **arsenic** is **33**.

A normal human spine has **33** vertebrae when the bones that form the coccyx are counted individually.

In the Bible,** Jesus’s age** when he was crucified was **33** (Hence 33AD)

Islamic prayer beads are generally arranged in sets of **33**.

In reference to vinyl gramophone records, **33** represents a type of record (known as an LP or long-playing record) with a speed of **33** 1/3 revolutions per minute.

In the English Premier league, the former Chelsea goal-keeper Petr Cech selected the squad number **33** on signing for Arsenal FC in June 2015. He cited that it represented his age **33**, his 333 Premier League games and that he wanted to be the spine (with **33** vertebrae) of the team.

### Interesting Number

This interesting number is **8**.

**8** is a composite number. It is the first number that is neither prime nor semi-prime.

**8** is a power of 2 i.e. 2^{3}.

A number is divisible by **8** if the number formed by the last three digits are divisible by 8.

The number **8** is an **even** number.

The **factors** of **8** are 1, 2, 4 and 8 – so 8 is divisible by 4 numbers.

**8** is a **Fibonacci** number (3 + 5).

A **polygon** with **8** sides is called an **octagon**.

A **polyhedron** with **8** faces is called an **octahedron**. Each face is an equilateral triangle.

A **cube** has **8** vertices.

A **octahedron** has faces as 6 congruent squares and 8 congruent equilateral triangles.

In **Roman** Numerals the number **8** can be written as **VIII**.

**8** is the atomic number of **oxygen**.

All spiders have **8** legs.

A **byte** is **8 **bits.

There are **8 ****furlongs** in a mile.

### Interesting Number

This interesting number is **91**.

**91** is a triangle number.

**91** is the 27^{th} distinct **semiprime**.

The code of international direct dial phone calls to India is **91**.

The number **91** is an **odd **number.

The **factors** of **91** are 1, 7, 13, and 91 – so 91 is divisible by 4 numbers.

The only **prime factors** of **91** are 7 and 13.

**91**% as a fraction is 91/100 or 0.91 as a decimal.

In the binary number system **91** can be written as **1011011**.

In **Roman** Numerals the number **91** can be written as **XCI**.

If you travelled a distance of **91** miles then this would be equivalent to about 146 kilometers.

Also a length of **91** feet is equivalent to 28 meters.

A weight of **91** pounds is equivalent to 41.3 kilograms.

A temperature of **91** degree Celsius is about 196 degree Fahrenheit.

**91** is the atomic number of protactinium, an actinide.

### Interesting Number

This interesting number is **46**.

**46** is the number of **human chromosomes**.

**46** is the 16^{th} **semiprime**.

In geometry, the name of a **46** sided polygon is called a **tetracontakaihexagon**.

The number **46** is an **even** number - the 23rd **even** number to be precise.

The **factors** of **46** are 1, 2, 23 and 46 – so 46 is divisible by 4 numbers.

The only **prime factors** of **46** are 2 and 23

**46**% as a fraction is 23/50 or 0.46 as a decimal.

In the binary number system **46** can be written as **101110**.

In **Roman** Numerals the number **46** can be written as **XLVI**.

If you travelled a distance of **46** miles then this would be equivalent to 74 kilometers.

Also a length of **46** feet is equivalent to 14.0 meters.

A weight of **46** pounds is equivalent to 20.9 kilograms.

A temperature of **46** degree Celsius is about 115 degree Fahrenheit.

### Interesting Number

This interesting number is **89**.

**89** is the **24th Prime Number**.

**89** is a **Fibonacci number** and therefore a **Fibonacci Prime**.

**89** is the **10th Mersenne Prime**.

**89** is part of the **Pythagorean Triple **(39, 80, 89) because 39^{2} + 80^{2} = 89^{2}.

**89** is an atomic number of the element **actinium**.

### Interesting Number

This interesting number is **49**.

**49** is a **square** number. **49** = 7^{2}

**49** is the first square where the digits are squares (4 and 9).

**Arsenal Football Club**, in the English Premier League, had an unbeaten run of **49** games between May 2003 through to October 2004 when they lost to Manchester United. This remains a national record in English football.

**49** is the atomic number of the element **indium**.

The sum of the digits of the **square** of **49** (2401) is the **square root** of **49**.

**49** is **trimorphic**, that is, its **cube** ends in the same digits i.e. **49**^{3} = 1176**49**

### Interesting Number

This interesting number is **35**.

**35** is the sum of the first 5 triangle numbers. i.e. 1 + 3 + 6 + 10 + 15 = 35.

**35** is a tetrahedral number.

**35** is the number of ways 3 objects can be selected from 7 objects (a combination)

**35** is a semi-prime (a product of two prime numbers 5 x 7)

There are **35** hexominoes (polyominoes made from 6 squares)