Take b = 2.

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

2719 is prime.

b^((n-1)/2719)-1 mod n = 62534385, which is a unit, inverse 37979476.

919 is prime.

b^((n-1)/919)-1 mod n = 131542906, which is a unit, inverse 23919559.

(919 * 2719) divides n-1.

(919 * 2719)^2 > n.

n is prime by Pocklington's theorem.