Primality proof for n = 324689:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=223.html>223 is prime.</a>
<br>b^((n-1)/223)-1 mod n = 174687, which is a unit, inverse 211597.
<p><a href=13.html>13 is prime.</a>
<br>b^((n-1)/13)-1 mod n = 26003, which is a unit, inverse 218478.
<p>(13 * 223) divides n-1.
<p>(13 * 223)^2 > n.
<p>n is prime by Pocklington's theorem.