Primality proof for n = 281276467:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=46879411.html>46879411 is prime.</a>
<br>b^((n-1)/46879411)-1 mod n = 63, which is a unit, inverse 102688234.
<p>(46879411) divides n-1.
<p>(46879411)^2 > n.
<p>n is prime by Pocklington's theorem.