Primality proof for n = 162128261:

Take b = 2.

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

165437 is prime.
b^((n-1)/165437)-1 mod n = 98455886, which is a unit, inverse 139214439.

(165437) divides n-1.

(165437)^2 > n.

n is prime by Pocklington's theorem.