155

This number is a composite.

2² + 3! + 5! + 7² - 11 - 13 = 155. [Russ]

155 is the only three-digit number such that 155^155-155+1 is prime. [Opao]

The sum of primes between smallest and largest prime factor inclusive of itself, i.e., 5 + 7 + 11 + 13 + 17 + 19 + 23 + 29 + 31 = 155. [Post]

155 = prime(1+5+5) * π(1+5+5). It is the smallest number of this form. [Bajpai]

155 and 155+1 are the smallest pair of consecutive integers whose highest prime factors (31 and 13) are anagrams of each other. [Gaydos]