In number theory, a perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself (also known as its aliquot sum). Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself) i.e. σ1(n) = 2n.
Read more about Perfect Number: Examples, Discovery, Even Perfect Numbers, Odd Perfect Numbers, Minor Results, Related Concepts
Famous quotes containing the words perfect and/or number:
“There is no such thing as a perfect leader either in the past or present, in China or elsewhere. If there is one, he is only pretending, like a pig inserting scallions into its nose in an effort to look like an elephant.”
—Liu Shao-Ch’I (b. 1898)
“Can it be, that the Greek grammarians invented their dual number for the particular benefit of twins?”
—Herman Melville (1819–1891)