Primality proof for n = 245621:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=12281.html>12281 is prime.</a>
<br>b^((n-1)/12281)-1 mod n = 66091, which is a unit, inverse 70857.
<p>(12281) divides n-1.
<p>(12281)^2 > n.
<p>n is prime by Pocklington's theorem.