Primality proof for n = 447368281760320663747:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=26312496861293.html>26312496861293 is prime.</a>
<br>b^((n-1)/26312496861293)-1 mod n = 256341153081284713848, which is a unit, inverse 30623399940583875494.
<p>(26312496861293) divides n-1.
<p>(26312496861293)^2 > n.
<p>n is prime by Pocklington's theorem.