Primality proof for n = 2084989:
Take b = 2.
b^(n-1) mod n = 1.
593 is prime.
b^((n-1)/593)-1 mod n = 797253, which is a unit, inverse 422972.
293 is prime.
b^((n-1)/293)-1 mod n = 1173413, which is a unit, inverse 413690.
(293 * 593) divides n-1.
(293 * 593)^2 > n.
n is prime by Pocklington's theorem.