Primality proof for n = 859:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=13.html>13 is prime.</a>
<br>b^((n-1)/13)-1 mod n = 772, which is a unit, inverse 780.
<p><a href=11.html>11 is prime.</a>
<br>b^((n-1)/11)-1 mod n = 792, which is a unit, inverse 500.
<p>(11 * 13) divides n-1.
<p>(11 * 13)^2 > n.
<p>n is prime by Pocklington's theorem.