Divisibility Rules Checker

About this calculator

This tool tests a whole number against each divisor from 2 through 11 using the standard divisibility rules: divisible by 2 if the last digit is even, by 3 if the digit sum is divisible by 3, by 4 if the last two digits form a number divisible by 4, by 5 if it ends in 0 or 5, by 9 if the digit sum is divisible by 9, and by 11 if the alternating sum of its digits is divisible by 11, among others — showing the remainder for every divisor tested.

Students and teachers use divisibility rules to build number sense and check factorization or simplification work without doing long division, and the same rules are a common building block in mental math tricks and early number theory lessons.