Primality proof for n = 84869:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=433.html>433 is prime.</a>
<br>b^((n-1)/433)-1 mod n = 50133, which is a unit, inverse 1830.
<p>(433) divides n-1.
<p>(433)^2 > n.
<p>n is prime by Pocklington's theorem.