Primality proof for n = 1283159:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=641579.html>641579 is prime.</a>
<br>b^((n-1)/641579)-1 mod n = 3, which is a unit, inverse 427720.
<p>(641579) divides n-1.
<p>(641579)^2 > n.
<p>n is prime by Pocklington's theorem.