How probable is a probable prime?

( go to the article → https://www.johndcook.com/blog/2020/06/04/probable-prime/ )

A probable prime is a number that passes a test that all primes pass and that most composite numbers fail. Specifically, a Fermat probable prime is a number that passes Fermat’s primality test. Fermat’s test is the most commonly used, so that’s nearly always what anyone means by probable prime unless they’re more specific. A […]

June 4, 2020, 12:33 p.m.