Primality proof for n = 487:

Take b = 2.

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

3 is prime.
b^((n-1)/3)-1 mod n = 231, which is a unit, inverse 409.

(3^5) divides n-1.

(3^5)^2 > n.

n is prime by Pocklington's theorem.