Primality proof for n = 4156739:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=683.html>683 is prime.</a>
<br>b^((n-1)/683)-1 mod n = 259617, which is a unit, inverse 2477805.
<p><a href=179.html>179 is prime.</a>
<br>b^((n-1)/179)-1 mod n = 2368194, which is a unit, inverse 2699056.
<p>(179 * 683) divides n-1.
<p>(179 * 683)^2 > n.
<p>n is prime by Pocklington's theorem.