| has gloss | eng: In mathematics, and particularly in number theory, a primary pseudoperfect number is a number N that satisfies the Egyptian fraction equation :\sum_p|N}\frac1p + \frac1N = 1, where the sum is over only the prime divisors of N. Equivalently (as can be seen by multiplying this equation by N), :\sum_p|N}\fracN}p + 1 = N. Except for the exceptional primary pseudoperfect number 2, this expression gives a representation for N as a sum of a set of distinct divisors of N; therefore each such number (except 2) is pseudoperfect. |
