noun
Mathematical term for a number that divides another without a remainder. Used in arithmetic and number theory.
6の約数は1、2、3、6です。
The divisors of 6 are 1, 2, 3, and 6.
12と18の公約
Find the common divisors of 12 and 18.
因数 also means 'factor', but is more common in factorization contexts (e.g., prime factors). 約数 is the standard term for divisors in general.
From 約 (yaku, 'approximately' or 'to bind') and 数 (sū, 'number'). The term was coined in the Meiji period as a translation of the Western mathematical concept 'divisor'.