Primality proof for n = 4232756191:

Take b = 2.

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

1423 is prime.
b^((n-1)/1423)-1 mod n = 2133709772, which is a unit, inverse 515704736.

263 is prime.
b^((n-1)/263)-1 mod n = 547850884, which is a unit, inverse 3199132789.

(263 * 1423) divides n-1.

(263 * 1423)^2 > n.

n is prime by Pocklington's theorem.