Primality proof for n = 191039911:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=155317.html>155317 is prime.</a>
<br>b^((n-1)/155317)-1 mod n = 76243072, which is a unit, inverse 69522358.
<p>(155317) divides n-1.
<p>(155317)^2 > n.
<p>n is prime by Pocklington's theorem.