Primality proof for n = 55516481:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=397.html>397 is prime.</a>
<br>b^((n-1)/397)-1 mod n = 21072120, which is a unit, inverse 47286639.
<p><a href=23.html>23 is prime.</a>
<br>b^((n-1)/23)-1 mod n = 39987660, which is a unit, inverse 43750573.
<p>(23 * 397) divides n-1.
<p>(23 * 397)^2 > n.
<p>n is prime by Pocklington's theorem.