Primality proof for n = 77867:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=38933.html>38933 is prime.</a>
<br>b^((n-1)/38933)-1 mod n = 3, which is a unit, inverse 25956.
<p>(38933) divides n-1.
<p>(38933)^2 > n.
<p>n is prime by Pocklington's theorem.