Primality proof for n = 22111:
Take b = 2.
b^(n-1) mod n = 1.
67 is prime.
b^((n-1)/67)-1 mod n = 12682, which is a unit, inverse 21642.
3 is prime.
b^((n-1)/3)-1 mod n = 7857, which is a unit, inverse 19491.
(3 * 67) divides n-1.
(3 * 67)^2 > n.
n is prime by Pocklington's theorem.