Primality proof for n = 77912789:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=9227.html>9227 is prime.</a>
<br>b^((n-1)/9227)-1 mod n = 41124880, which is a unit, inverse 59525679.
<p>(9227) divides n-1.
<p>(9227)^2 > n.
<p>n is prime by Pocklington's theorem.