# 100

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Cardinalone hundred
Ordinal100th
(one hundredth)
Factorization22 × 52
Divisors1, 2, 4, 5, 10, 20, 25, 50, 100
Greek numeralΡ´
Roman numeralC, c
Binary11001002
Ternary102013
Senary2446
Octal1448
Duodecimal8412
Greek numeralρ
Arabic١٠٠
Bengali১০০
Chinese numeral佰,百
Devanagari१००
Hebrewק
Khmer១០០
ArmenianՃ
Tamil௱, க௦௦
Thai๑๐๐
Egyptian hieroglyph𓍢
Babylonian cuneiform𒐕𒐏

100 or one hundred (Roman numeral: C)[1] is the natural number following 99 and preceding 101.

## 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 centum meaning "by the hundred" in Latin), with 100% being a full amount.

100 is a Harshad number in decimal, and also in base-four, a base in-which it is also a self-descriptive number.[2][3]

100 is the sum of the first nine prime numbers, from 2 through 23.[4] It is also divisible by the number of primes below it, 25.[5]

100 cannot be expressed as the difference between any integer and the total of coprimes below it, making it a noncototient.[6]

100 has a reduced totient of 20, and an Euler totient of 40.[7][8] A totient value of 100 is obtained from four numbers: 101, 125, 202, and 250.

100 can be expressed as a sum of some of its divisors, making it a semiperfect number.[9] The geometric mean of its nine divisors is 10.

100 is the sum of the cubes of the first four positive integers (100 = 13 + 23 + 33 + 43).[10] This is related by Nicomachus's theorem to the fact that 100 also equals the square of the sum of the first four positive integers: 100 = 102 = (1 + 2 + 3 + 4)2.[11]

100 = 26 + 62, thus 100 is the seventh Leyland number.[12] 100 is also the seventeenth Erdős–Woods number, and the fourth 18-gonal number.[13][14]

The 100th prime number is 541, which returns ${\displaystyle 0}$ for the Mertens function.[15] It is the 10th star number[16] (whose digit sum also adds to 10 in decimal).

There are exactly 100 prime numbers in base-ten whose digits are in strictly ascending order (e.g. 239, 2357, etc.).[17] The last such prime number is 23456789, which contains eight consecutive integers as digits.

## In science

One hundred is the atomic number of fermium, an actinide, and the last of the heavy metals that can be created through neutron bombardment.

On the Celsius scale, 100 degrees is the boiling temperature of pure water at sea level.

The Kármán line lies at an altitude of 100 kilometres (62 mi) above the Earth's sea level and is commonly used to define the boundary between Earth's atmosphere and outer space.

## In money

Most of the world's currencies are divided into 100 subunits; for example, one euro is one hundred cents and one pound sterling is one hundred pence.

By specification, 100 euro notes feature a picture of a Rococo gateway on the obverse and a Baroque bridge on the reverse.

The U.S. hundred-dollar bill has Benjamin Franklin's portrait; the "Benjamin" is the largest U.S. bill in print. American savings bonds of \$100 have Thomas Jefferson's portrait, while American \$100 treasury bonds have Andrew Jackson's portrait.

## In other fields

One hundred is also:

## References

1. ^ Reinforced by but not originally derived from Latin centum.
2. ^ "Sloane's A005349 : Niven (or Harshad) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
3. ^ Sloane, N. J. A. (ed.). "Sequence A108551 (Self-descriptive numbers in various bases represented in base 10)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-08.
4. ^ Sloane, N. J. A. (ed.). "Sequence A007504 (Sum of the first n primes.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
5. ^ Sloane, N. J. A. (ed.). "Sequence A057809 (Numbers n such that pi(n) divides n.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
6. ^ Sloane, N. J. A. (ed.). "Sequence A005278 (Noncototients)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-08.
7. ^ Sloane, N. J. A. (ed.). "Sequence A002322 (Reduced totient function)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-08.
8. ^ Sloane, N. J. A. (ed.). "Sequence A000010 (Euler totient function)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
9. ^ Sloane, N. J. A. (ed.). "Sequence A005835 (Pseudoperfect (or semiperfect) numbers n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-08.
10. ^ Sloane, N. J. A. (ed.). "Sequence A025403 (Numbers that are the sum of 4 positive cubes in exactly 1 way.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-08.
11. ^
12. ^ "Sloane's A076980 : Leyland numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
13. ^
14. ^ "Sloane's A051870 : 18-gonal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
15. ^ Sloane, N. J. A. (ed.). "Sequence A028442 (Numbers k such that Mertens's function M(k) (A002321) is zero.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2023-09-02.
16. ^ Sloane, N. J. A. (ed.). "Sequence A003154". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2023-09-02.
17. ^ Sloane, N. J. A. (ed.). "Sequence A052015 (Primes with distinct digits in ascending order.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-11-05.
18. ^ see Duodecimal § Origin
19. ^ Insights, September 28, 2011.
20. ^ Leo Rosten, The Joys of Yiddish (1968), page 52.
21. ^ Grasso, John (2013), Historical Dictionary of Football, Scarecrow Press, p. 133, ISBN 9780810878570.
22. ^ "Basketball Legend Chamberlain Dies at 63". www.washingtonpost.com. Retrieved 2023-08-07.