Take b = 2.

b^(n-1) mod n = 1.

223 is prime.

b^((n-1)/223)-1 mod n = 4858170, which is a unit, inverse 4776110.

151 is prime.

b^((n-1)/151)-1 mod n = 3461388, which is a unit, inverse 5838524.

(151 * 223) divides n-1.

(151 * 223)^2 > n.

n is prime by Pocklington's theorem.