Primality proof for n = 1890206079784759632867687927237221931415993:
<p>Take b = 2.
<p>b^(n-1) mod n = 1.
<p><a href=143868846306805039381043.html>143868846306805039381043 is prime.</a>
<br>b^((n-1)/143868846306805039381043)-1 mod n = 991889672936538679985176154967467539568962, which is a unit, inverse 1074257486403253704905773364364017704621796.
<p>(143868846306805039381043) divides n-1.
<p>(143868846306805039381043)^2 > n.
<p>n is prime by Pocklington's theorem.