Primality proof for n = 720869:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=10601.html>10601 is prime.</a>
<br>b^((n-1)/10601)-1 mod n = 357937, which is a unit, inverse 411018.
<p>(10601) divides n-1.
<p>(10601)^2 > n.
<p>n is prime by Pocklington's theorem.