Primality proof for n = 1609403:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=593.html>593 is prime.</a>
<br>b^((n-1)/593)-1 mod n = 518584, which is a unit, inverse 1355953.
<p><a href=59.html>59 is prime.</a>
<br>b^((n-1)/59)-1 mod n = 860232, which is a unit, inverse 488642.
<p>(59 * 593) divides n-1.
<p>(59 * 593)^2 > n.
<p>n is prime by Pocklington's theorem.