Primality proof for n = 67153:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=1399.html>1399 is prime.</a>
<br>b^((n-1)/1399)-1 mod n = 766, which is a unit, inverse 66890.
<p>(1399) divides n-1.
<p>(1399)^2 > n.
<p>n is prime by Pocklington's theorem.