Primality proof for n = 109829:
Take b = 2.
b^(n-1) mod n = 1.
27457 is prime. b^((n-1)/27457)-1 mod n = 15, which is a unit, inverse 7322.
(27457) divides n-1.
(27457)^2 > n.
n is prime by Pocklington's theorem.