Take b = 2.
b^(n-1) mod n = 1.
323757349 is prime. b^((n-1)/323757349)-1 mod n = 492641104943, which is a unit, inverse 1172235478081.
(323757349) divides n-1.
(323757349)^2 > n.
n is prime by Pocklington's theorem.