Primality proof for n = 878766598991:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=1814921.html>1814921 is prime.</a>
<br>b^((n-1)/1814921)-1 mod n = 300206661287, which is a unit, inverse 158983999210.
<p>(1814921) divides n-1.
<p>(1814921)^2 > n.
<p>n is prime by Pocklington's theorem.