Primality proof for n = 3935887:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=12377.html>12377 is prime.</a>
<br>b^((n-1)/12377)-1 mod n = 3742781, which is a unit, inverse 2804747.
<p>(12377) divides n-1.
<p>(12377)^2 > n.
<p>n is prime by Pocklington's theorem.