Primality proof for n = 27748561:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=199.html>199 is prime.</a>
<br>b^((n-1)/199)-1 mod n = 7685141, which is a unit, inverse 16164448.
<p><a href=83.html>83 is prime.</a>
<br>b^((n-1)/83)-1 mod n = 13722120, which is a unit, inverse 22679122.
<p>(83 * 199) divides n-1.
<p>(83 * 199)^2 > n.
<p>n is prime by Pocklington's theorem.