100

One hundred (100; the Roman numeral is C for centum) is the natural number following 99 and preceding 101. The square of 10 (in scientific notation it is written as 10²), it is a composite number, with its divisors being 2, 4, 5, 10, 20, 40 and 50, and its factorization is

$100=2^{2}\cdot 5^{2}$

The standard SI prefix for a hundred is "hecto-". This number is the sum of the first nine prime numbers, as well as the sum of two prime numbers (47 + 53). 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:

• 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 denomination of the U.S. dollar 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.

See also: hundred (division). See also: ninety, one hundred, one hundred and ten, two hundred

This article is about the number. For the year AD 100, see 100.