Primality proof for n = 28430359:

Take b = 2.

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

25339 is prime.
b^((n-1)/25339)-1 mod n = 25499506, which is a unit, inverse 332810.

(25339) divides n-1.

(25339)^2 > n.

n is prime by Pocklington's theorem.