# 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 ${\displaystyle 2^{2}\cdot 5^{2}}$ Divisors 2, 4, 5, 10,20, 25, 50 Roman numeral C Unicode representation of Roman numeral Ⅽ, ⅽ prefixes hecto-/hect- (from Greek) centi- (from Latin) Binary 1100100 Hexadecimal 64 Hebrew ק (Qof)

## In mathematics

One hundred is the square of 10 (in scientific notation it is written as ${\displaystyle 10^{2}}$). 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: