133 (number)

Last updated
132 133 134
Cardinal one hundred thirty-three
Ordinal 133rd
(one hundred thirty-third)
Factorization 7 × 19
Divisors 1, 7, 19, 133
Greek numeral ΡΛΓ´
Roman numeral CXXXIII, cxxxiii
Binary 100001012
Ternary 112213
Senary 3416
Octal 2058
Duodecimal B112
Hexadecimal 8516

133 (one hundred [and] thirty-three) is the natural number following 132 and preceding 134.

In mathematics

133 is an n whose divisors (excluding n itself) added up divide φ(n). It is an octagonal number [1] and a happy number. [2]

133 is a Harshad number, because it is divisible by the sum of its digits.

133 is a repdigit in base 11 (111) and base 18 (77), whilst in base 20 it is a cyclic number formed from the reciprocal of the number three.

133 is a semiprime: a product of two prime numbers, namely 7 and 19. Since those prime factors are Gaussian primes, this means that 133 is a Blum integer.

133 is the number of compositions of 13 into distinct parts. [3]

133 is the 100th composite number.

References

  1. "Sloane's A000567 : Octagonal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  2. "Sloane's A007770 : Happy numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-27.
  3. Sloane, N. J. A. (ed.). "SequenceA032020(Number of compositions (ordered partitions) of n into distinct parts)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2022-05-24.