The factors of 220, excluding 220 itself, are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110 and sum to 284; the factors of 284, excluding 284 itself, are 1, 2, 4, 71, and 142, and sum to 220; hence 220 and 284 are amicable numbers.
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Amicable numbers — Amicable Am i*ca*ble, a. [L. amicabilis, fr. amicus friend, fr. amare to love. See {Amiable}.] Friendly; proceeding from, or exhibiting, friendliness; after the manner of friends; peaceable; as, an amicable disposition, or arrangement. [1913… … The Collaborative International Dictionary of English
amicable numbers — plural noun (mathematics) see ↑friendly numbers under ↑friend • • • Main Entry: ↑amicable … Useful english dictionary
Amicable number — Amicable numbers are two different numbers so related that the sum of the proper divisors of the one is equal to the other, one being considered as a proper divisor but not the number itself. Such a pair is (220, 284); for the proper divisors of… … Wikipedia
Amicable — Am i*ca*ble, a. [L. amicabilis, fr. amicus friend, fr. amare to love. See {Amiable}.] Friendly; proceeding from, or exhibiting, friendliness; after the manner of friends; peaceable; as, an amicable disposition, or arrangement. [1913 Webster] That … The Collaborative International Dictionary of English
Amicable action — Amicable Am i*ca*ble, a. [L. amicabilis, fr. amicus friend, fr. amare to love. See {Amiable}.] Friendly; proceeding from, or exhibiting, friendliness; after the manner of friends; peaceable; as, an amicable disposition, or arrangement. [1913… … The Collaborative International Dictionary of English
amicable number — noun Either of a pair of amicable numbers … Wiktionary
amicable number — noun : either of two numbers each of which is equal to the sum of all the submultiples of the other * * * Math. either of a pair of positive integers in which each member is equal to the sum of the submultiples of the other, as 220 and 284 … Useful english dictionary
friendly numbers — plural noun (mathematics) Pairs of numbers each of which is the sum of the factors of the other, including unity (also called amicable numbers; cf ↑perfect number) • • • Main Entry: ↑friend … Useful english dictionary
mathematics — /math euh mat iks/, n. 1. (used with a sing. v.) the systematic treatment of magnitude, relationships between figures and forms, and relations between quantities expressed symbolically. 2. (used with a sing. or pl. v.) mathematical procedures,… … Universalium
number theory — Math. the study of integers and their relation to one another. Also called theory of numbers. [1910 15] * * * Branch of mathematics concerned with properties of and relations among integers. It is a popular subject among amateur mathematicians… … Universalium
