Primality proof for n = 26687:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=1213.html>1213 is prime.</a>
<br>b^((n-1)/1213)-1 mod n = 4444, which is a unit, inverse 16244.
<p>(1213) divides n-1.
<p>(1213)^2 > n.
<p>n is prime by Pocklington's theorem.