Primality proof for n = 4048673:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=6659.html>6659 is prime.</a>
<br>b^((n-1)/6659)-1 mod n = 1785997, which is a unit, inverse 3486811.
<p>(6659) divides n-1.
<p>(6659)^2 > n.
<p>n is prime by Pocklington's theorem.