Primality proof for n = 2796876191:
Take b = 2.
b^(n-1) mod n = 1.
14720401 is prime. b^((n-1)/14720401)-1 mod n = 888709075, which is a unit, inverse 2273013330.
(14720401) divides n-1.
(14720401)^2 > n.
n is prime by Pocklington's theorem.