Primality proof for n = 604703486621959:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=216558437.html>216558437 is prime.</a>
<br>b^((n-1)/216558437)-1 mod n = 149757495094359, which is a unit, inverse 340097112345405.
<p>(216558437) divides n-1.
<p>(216558437)^2 > n.
<p>n is prime by Pocklington's theorem.