195 (number)195 is the natural number following 194 and preceding 196.In mathematics195 is: the sum of eleven consecutive primes: 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37 the smallest number expressed as a sum of distinct squares in 16 different ways a centered tetrahedral number in the middle of a prime quadruplet.