Primality proof for n = 7180178067871:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=1798367.html>1798367 is prime.</a>
<br>b^((n-1)/1798367)-1 mod n = 7170372988273, which is a unit, inverse 3163238940460.
<p><a href=133087.html>133087 is prime.</a>
<br>b^((n-1)/133087)-1 mod n = 2423926101171, which is a unit, inverse 5132894331958.
<p>(133087 * 1798367) divides n-1.
<p>(133087 * 1798367)^2 > n.
<p>n is prime by Pocklington's theorem.