Primality proof for n = 40024942543673:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=25396537147.html>25396537147 is prime.</a>
<br>b^((n-1)/25396537147)-1 mod n = 24760559515411, which is a unit, inverse 36222238642773.
<p>(25396537147) divides n-1.
<p>(25396537147)^2 > n.
<p>n is prime by Pocklington's theorem.