Primality proof for n = 2459:

Take b = 2.

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

1229 is prime.
b^((n-1)/1229)-1 mod n = 3, which is a unit, inverse 820.

(1229) divides n-1.

(1229)^2 > n.

n is prime by Pocklington's theorem.