Primality proof for n = 1206941:

Take b = 2.

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

233 is prime.
b^((n-1)/233)-1 mod n = 445776, which is a unit, inverse 66916.

37 is prime.
b^((n-1)/37)-1 mod n = 185486, which is a unit, inverse 793173.

(37 * 233) divides n-1.

(37 * 233)^2 > n.

n is prime by Pocklington's theorem.