# 133 (number)

 ← 132 133 134 →
Cardinal one hundred thirty-three
Ordinal 133rd
(one hundred and thirty-third)
Factorization 7 × 19
Divisors 1, 7, 19, 133
Roman numeral CXXXIII
Binary 100001012
Ternary 112213
Quaternary 20114
Quinary 10135
Senary 3416
Octal 2058
Duodecimal B112
Vigesimal 6D20
Base 36 3P36

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 and a Harshad number. It is also a happy number.

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 also:

## References

1. ^ Porter, Darwin; Danforth Prince (2009). Frommer's Austria. Hoboken, New Jersey: Frommer's. p. 482. ISBN 978-0-470-39897-5.