Primality proof for n = 26979779:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=26399.html>26399 is prime.</a>
<br>b^((n-1)/26399)-1 mod n = 11632, which is a unit, inverse 9808931.
<p>(26399) divides n-1.
<p>(26399)^2 > n.
<p>n is prime by Pocklington's theorem.