Primality proof for n = 17171153:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=20249.html>20249 is prime.</a>
<br>b^((n-1)/20249)-1 mod n = 11619796, which is a unit, inverse 13961520.
<p>(20249) divides n-1.
<p>(20249)^2 > n.
<p>n is prime by Pocklington's theorem.