Primality proof for n = 24390926906057:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=7144903.html>7144903 is prime.</a>
<br>b^((n-1)/7144903)-1 mod n = 23390616675106, which is a unit, inverse 7370921774782.
<p>(7144903) divides n-1.
<p>(7144903)^2 > n.
<p>n is prime by Pocklington's theorem.