Mathematical term for a number that divides another without a remainder. Used in arithmetic and number theory.
The divisors of 6 are 1, 2, 3, and 6.
12と18の公約数を求めなさい。
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.
common divisor; common factor
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'.