Primality proof for n = 20492504424583:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=3415417404097.html>3415417404097 is prime.</a>
<br>b^((n-1)/3415417404097)-1 mod n = 63, which is a unit, inverse 19191393032546.
<p>(3415417404097) divides n-1.
<p>(3415417404097)^2 > n.
<p>n is prime by Pocklington's theorem.