# 155 (number)

 ← 154 155 156 →
Cardinal one hundred fifty-five
Ordinal 155th
(one hundred fifty-fifth)
Factorization 5 × 31
Divisors 1, 5, 31, 155
Roman numeral CLV
Binary 100110112
Ternary 122023
Quaternary 21234
Quinary 11105
Senary 4156
Octal 2338
Duodecimal 10B12
Vigesimal 7F20
Base 36 4B36

155 (one hundred [and] fifty-five) is the natural number following 154 and preceding 156.

## In mathematics

155 is:

There are 155 primitive permutations of degree 81.

If one adds up all the primes from the least through the greatest prime factors of 155, that is, 5 and 31, the result is 155. (sequence A055233 in the OEIS) Only three other "small" semiprimes (10, 39, and 371) share this attribute.

155 is also: