133 (number)

133 1, 7, 19, 133 CXXXIII 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 numberhttps://oeis.org/A000567 Sloane's A000567 : Octagonal numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-05-27 and a happy number.https://oeis.org/A007770 Sloane's A007770 : Happy numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-05-27 133 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.A032020 Number of compositions (ordered partitions) of n into distinct parts 2022-05-24 133 is the 100th composite number. References 1 Category:Integers