## Interesting Numbers

### 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.

1966 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:

72 + 22 + 12 = 62 + 32 + 32 = 52 + 52 + 22 = 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 1945.

### 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 Opus59 consists of the three so-called Razumovsky Quartets

The 1960s song “59th" 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 13th 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 41st 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 21st 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 44th 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

51st 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 19th 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 22nd 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 32 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 063 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 028 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.

702 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 12th 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 1011 in binary.

11 is the 5th 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 11am on the 11th day of the 11th 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 16th 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 23 + 33 + 43

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 52

25 is 11001 in binary.

25 is the smallest square that is also the sum of two non-zero squares (25 = 32 + 42)

25 is a square number 52 = 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 = 52) AND 1 less than a cube (27 = 33)

### 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. 42 + 52 + 62

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 –195.79oC.

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: 15 + 25

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. 23.

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 bits.

There are furlongs in a mile.

### Interesting Number

This interesting number is 91.

91 is a triangle number.

91 is the 27th 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 16th 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 392 + 802 = 892.

89 is an atomic number of the element actinium.

### Interesting Number

This interesting number is 49.

49 is a square number. 49 = 72

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. 493 = 117649

### 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)