In medieval contexts, it may be described as the short hundred or five score in order to differentiate the English and Germanic use of "hundred" to describe the long hundred of six score or 120.

100 is the square of 10 (in scientific notation it is written as 10²). The standard SI prefix for a hundred is "hecto-".

100 is the basis of percentages (per cent meaning "per hundred" in Latin), with 100% being a full amount.

100 is the sum of the first nine prime numbers, as well as the sum of some pairs of prime numbers e.g., 3 + 97, 11 + 89, 17 + 83, 29 + 71, 41 + 59, and 47 + 53.

100 is the sum of the cubes of the first four integers (100 = 1³ + 2³ + 3³ + 4³). This is related by Nicomachus's theorem to the fact that 100 also equals the square of the sum of the first four integers: 100 = 10² = (1 + 2 + 3 + 4)².

2⁶ + 6² = 100, thus 100 is a Leyland number.

100 is an 18-gonal number. It is divisible by the number of primes below it, 25 in this case. It can not be expressed as the difference between any integer and the total of coprimes below it, making it a noncototient. It can be expressed as a sum of some of its divisors, making it a semiperfect number.

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