155 (number)


155 is the natural number following 154 and preceding 156.

In mathematics

155 is:
There are 155 primitive permutation groups 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. Only three other "small" semiprimes share this attribute.

In the military

155 is also: