Primality proof for n = 15643211:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=142211.html>142211 is prime.</a>
<br>b^((n-1)/142211)-1 mod n = 7946300, which is a unit, inverse 4998333.
<p>(142211) divides n-1.
<p>(142211)^2 > n.
<p>n is prime by Pocklington's theorem.