Primality proof for n = 3270593687:

Take b = 2.

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

1635296843 is prime.
b^((n-1)/1635296843)-1 mod n = 3, which is a unit, inverse 1090197896.

(1635296843) divides n-1.

(1635296843)^2 > n.

n is prime by Pocklington's theorem.