Primality proof for n = 671065561:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=991.html>991 is prime.</a>
<br>b^((n-1)/991)-1 mod n = 159542748, which is a unit, inverse 539399916.
<p><a href=19.html>19 is prime.</a>
<br>b^((n-1)/19)-1 mod n = 74316606, which is a unit, inverse 647427994.
<p><a href=11.html>11 is prime.</a>
<br>b^((n-1)/11)-1 mod n = 90255800, which is a unit, inverse 125939268.
<p>(11 * 19 * 991) divides n-1.
<p>(11 * 19 * 991)^2 > n.
<p>n is prime by Pocklington's theorem.