Primality proof for n = 669274658641:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=71741.html>71741 is prime.</a>
<br>b^((n-1)/71741)-1 mod n = 508527992117, which is a unit, inverse 610938685323.
<p><a href=617.html>617 is prime.</a>
<br>b^((n-1)/617)-1 mod n = 85948266743, which is a unit, inverse 407961336565.
<p>(617 * 71741) divides n-1.
<p>(617 * 71741)^2 > n.
<p>n is prime by Pocklington's theorem.