1.NounAn integer that possesses at least one characteristic of a prime number without actually being prime. The characteristic is typically chosen to make such "false primes" very rare.
2.NounA Fermat pseudoprime; a composite integer n satisfying
b
n
−
1
≡
1
(
mod
n
)
{\displaystyle b^{n-1}\equiv 1{\pmod {n}}}
for some integer b such that b > 1.