Primality proof for n = 26889041:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=336113.html>336113 is prime.</a>
<br>b^((n-1)/336113)-1 mod n = 15328821, which is a unit, inverse 13939937.
<p>(336113) divides n-1.
<p>(336113)^2 > n.
<p>n is prime by Pocklington's theorem.