345

This number is a composite.

345*2^345 - 345 - 2^345 is prime. [Noll]

3!+4!+5! plus one is a palindromic prime . It is the smallest 3-digit number of this form, with consecutive digits in ascending order. [Bajpai]

345 is the sum of the first 6 Fibonacci primes. [Honaker]

The first 345 digits in decimal expansion of tau form a prime, where tau = 2π. [Bajpai]