Primality proof for n = 963926494829235139921:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=880691887.html>880691887 is prime.</a>
<br>b^((n-1)/880691887)-1 mod n = 940251452989926706616, which is a unit, inverse 335737063190318778704.
<p><a href=198280883.html>198280883 is prime.</a>
<br>b^((n-1)/198280883)-1 mod n = 653784643977091094325, which is a unit, inverse 166622018899174174028.
<p>(198280883 * 880691887) divides n-1.
<p>(198280883 * 880691887)^2 > n.
<p>n is prime by Pocklington's theorem.