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100 or one hundred (Roman numeral: Ⅽ) is the natural number following 99 and preceding 101. 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. ==In mathematics== 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: . 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. 100 is a Harshad number in base 10, and also in base 4, and in that base it is a self-descriptive number. There are exactly 100 prime numbers whose digits are in strictly ascending order (e.g. 239, 2357 etc.). 100 is the smallest number whose common logarithm is a prime number (i.e. 10''n'' for which ''n'' is prime). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「100 (number)」の詳細全文を読む スポンサード リンク
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