Primality proof for n = 5879:

Take b = 2.

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

2939 is prime.
b^((n-1)/2939)-1 mod n = 3, which is a unit, inverse 1960.

(2939) divides n-1.

(2939)^2 > n.

n is prime by Pocklington's theorem.