# 100 number

**100** (the Roman numeral is C for *centum*) is the natural number following 99 and preceding 101.

Template:Numbers 100s | |

Cardinal | one hundred |

Ordinal | 100th (one hundredth) |

Factorization | |

Divisors | 2, 4, 5, 10, 20, 25, 50 |

Roman numeral | C |

Unicode representation of Roman numeral | Ⅽ, ⅽ |

prefixes | hecto-/hect- (from Greek) |

Binary | 1100100 |

Hexadecimal | 64 |

Hebrew | ק (Qof) |

## In mathematics

**One hundred** is the square of 10 (in scientific notation it is written as ). The standard SI prefix for a hundred is "hecto-".

It is the sum of the first nine prime numbers, as well as the sum of two prime numbers (47 + 53), and the sum of the cubes of the first four integers.

But perhaps this number is most important as the basis of percentages (literally "per hundred"), with 100% being a full amount.

One hundred is also an 18-gonal number. It is divisible by the number of primes below it, 25 in this case. But it can not be expressed as the difference between any integer and the total of coprimes below it, making it a noncototient.

100 is a Harshad number in base 10, and also in base 4, and in that base it is a self-descriptive number.

## In astronomy

The Messier object M100, a magnitude 10.5 spiral galaxy in the constellation Coma Berenices.

The New General Catalogue object NGC 100, a magnitude 13.3 spiral galaxy in the constellation Pisces.

## In other fields

**One hundred** is also:

- The atomic number of fermium, an actinide.
- In degrees Celsius, the boiling temperature of water at sea level.
- The number of years in a century.
- The number of pounds in an American short hundredweight.
- The number of subunits into which many of the world's currencies are divided; for example, one euro is one hundred cents and one Pound Sterling is one hundred pence.
- The number of verses in the pop song 99 Bottles of Beer
- The denomination of the U.S. hundred-dollar bill with Benjamin Franklin's portrait.
- The denomination of American savings bonds with Thomas Jefferson's portrait.
- The denomination of American treasury bonds with Andrew Jackson's portrait.
- The number of tiles in a standard Scrabble set.
- The number of entries in many "all time" lists voted for by the public, e.g. The 100 Best Films, The 100 Worst Pop Songs
- In India, 100 is the police telephone number.
- In United Kingdom, 100 is the operator telephone number
- The year AD
**100**or 100 BC. - Hundred Days, aka the Waterloo Campaign
- The number of the first folder of photos in the DCIM folder created by a brand-new digital camera (or after a change of memory card if the camera is set to auto-reset numbering).
- The number of poems in the Japanese poetry anthology Hyakunin Isshu.

## See also

ca:Cent da:100 (tal) es:Cien eo:Cent fr:100 (nombre) ko:100 ia:100 it:Cento (numero) nl:Honderd (getal) ja:100 pl:Sto ru:100 (число) sl:100 (število) sv:100 (tal) zh:100