325

This number is a composite.

325!/(3!*2!*5!)-(3!*2!*5!) + 1 is prime. [Patterson]

The smallest triangular number that is average of the sum of squares of two consecutive primes, i.e., (17^2 + 19^2)/2 = 325. [Bajpai]

There are 325 instances of {p, p + 6, p + 12, p + 18} all being prime, less than 1 million. [Homewood]