155 (number)
155 (one hundred [and] fifty-five) 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 (10, 39, and 371) share this attribute. In other fields. 155 is also: