Primality proof for n = 17389:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=23.html>23 is prime.</a>
<br>b^((n-1)/23)-1 mod n = 4347, which is a unit, inverse 17385.
<p><a href=7.html>7 is prime.</a>
<br>b^((n-1)/7)-1 mod n = 16990, which is a unit, inverse 1874.
<p>(7 * 23) divides n-1.
<p>(7 * 23)^2 > n.
<p>n is prime by Pocklington's theorem.