Primality proof for n = 16309109:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=21347.html>21347 is prime.</a>
<br>b^((n-1)/21347)-1 mod n = 11266108, which is a unit, inverse 8206352.
<p>(21347) divides n-1.
<p>(21347)^2 > n.
<p>n is prime by Pocklington's theorem.