100

Last updated
99 100 101
Cardinal one hundred
Ordinal 100th
(one hundredth)
Factorization 22 × 52
Divisors 1, 2, 4, 5, 10, 20, 25, 50, 100
Greek numeral Ρ´
Roman numeral C, c
Binary 11001002
Ternary 102013
Senary 2446
Octal 1448
Duodecimal 8412
Hexadecimal 6416
Greek numeral ρ
Arabic ١٠٠
Bengali ১০০
Chinese numeral 佰,百
Devanagari १००
Hebrew ק
Khmer ១០០
Armenian Ճ
Tamil ௱, க௦௦
Thai ๑๐๐
Egyptian hieroglyph 𓍢
Babylonian cuneiform 𒐕𒐏

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

Contents

In mathematics

100 as the sum of the first positive cubes Cube-sum-100.png
100 as the sum of the first positive cubes

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]

It is the 10th star number [15] (whose digit sum also adds to 10 in decimal).

In history

In money

Hundred rupee note India Hundred rupee note India.jpg
Hundred rupee note India

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, Series 2009 New100front.jpg
The U.S. hundred-dollar bill, Series 2009

The U.S. hundred-dollar bill has Benjamin Franklin's portrait; the "Benjamin" is the largest U.S. bill in print.

In other fields

One hundred is also:

See 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.). "SequenceA108551(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.). "SequenceA007504(Sum of the first n primes.)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  5. Sloane, N. J. A. (ed.). "SequenceA057809(Numbers n such that pi(n) divides n.)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  6. Sloane, N. J. A. (ed.). "SequenceA005278(Noncototients)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2022-12-08.
  7. Sloane, N. J. A. (ed.). "SequenceA002322(Reduced totient function)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2022-12-08.
  8. Sloane, N. J. A. (ed.). "SequenceA000010(Euler totient function)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  9. Sloane, N. J. A. (ed.). "SequenceA005835(Pseudoperfect (or semiperfect) numbers n)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2022-12-08.
  10. Sloane, N. J. A. (ed.). "SequenceA025403(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. Sloane, N. J. A. (ed.). "SequenceA000537(Sum of first n cubes; or n-th triangular number squared)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  12. "Sloane's A076980 : Leyland numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  13. Sloane, N. J. A. (ed.). "SequenceA059756(Erdős-Woods numbers: the length of an interval of consecutive integers with property that every element has a factor in common with one of the endpoints)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2022-11-30.
  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.). "SequenceA003154". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2023-09-02.
  16. see Duodecimal § Origin