Primality proof for n = 1898722439:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=868583.html>868583 is prime.</a>
<br>b^((n-1)/868583)-1 mod n = 1209578668, which is a unit, inverse 947448799.
<p>(868583) divides n-1.
<p>(868583)^2 > n.
<p>n is prime by Pocklington's theorem.