Primality proof for n = 208469:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=211.html>211 is prime.</a>
<br>b^((n-1)/211)-1 mod n = 3834, which is a unit, inverse 115218.
<p><a href=19.html>19 is prime.</a>
<br>b^((n-1)/19)-1 mod n = 100400, which is a unit, inverse 3262.
<p>(19 * 211) divides n-1.
<p>(19 * 211)^2 > n.
<p>n is prime by Pocklington's theorem.