English Dictionary

amicable number

noun

(number theory) One of a pair of numbers having the property that the sum of the divisors of each, excluding itself, is equal to the other number.

Amicable numbers are pairs of numbers where each number is the sum of the proper divisors of the other number.

意味（1）

(number theory) One of a pair of numbers having the property that the sum of the divisors of each, excluding itself, is equal to the other number.

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.