Primality proof for n = 91309423:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=208469.html>208469 is prime.</a>
<br>b^((n-1)/208469)-1 mod n = 42114267, which is a unit, inverse 3379069.
<p>(208469) divides n-1.
<p>(208469)^2 > n.
<p>n is prime by Pocklington's theorem.