hyperperfect number noun1 •Any natural number n for which, for some positive integer k, n = 1 + k(σ(n) - n - 1), where σ(n) is the sum of the positive divisors of n.[…] the asymptotic density of all hyperperfect numbers, that is, numbers m for which m | σ(m), is equal to zero. — 1966 formshyperperfect numbers
