Primality proof for n = 213441916511:
Take b = 2.
b^(n-1) mod n = 1.
292386187 is prime.
b^((n-1)/292386187)-1 mod n = 47282696164, which is a unit, inverse 209712463866.
(292386187) divides n-1.
(292386187)^2 > n.
n is prime by Pocklington's theorem.