Primality proof for n = 411679:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=22871.html>22871 is prime.</a>
<br>b^((n-1)/22871)-1 mod n = 262143, which is a unit, inverse 346308.
<p>(22871) divides n-1.
<p>(22871)^2 > n.
<p>n is prime by Pocklington's theorem.