Primality proof for n = 12320708804681:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=28287053.html>28287053 is prime.</a>
<br>b^((n-1)/28287053)-1 mod n = 5861960871100, which is a unit, inverse 3774419832656.
<p>(28287053) divides n-1.
<p>(28287053)^2 > n.
<p>n is prime by Pocklington's theorem.