 Thus, there is a one-to-one correspondence between even perfect numbers and Mersenne primes; each Mersenne prime generates one even perfect number, and vice versa.This result is often referred to as the Euclid–Euler theorem.An exhaustive search by the GIMPS distributed computing project has shown that the first 47 even perfect numbers are 2"p"−1(2"p" − 1) for
Four higher perfect numbers have also been discovered, namely those for which "p" = 57885161, 74207281, 77232917, and 82589933, though there may be others within this range.