Primality proof for n = 1869236796843064056413:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=5195037399650551.html>5195037399650551 is prime.</a>
<br>b^((n-1)/5195037399650551)-1 mod n = 815890344222225492706, which is a unit, inverse 267328296273347899544.
<p>(5195037399650551) divides n-1.
<p>(5195037399650551)^2 > n.
<p>n is prime by Pocklington's theorem.