This paper studies the numeral divisibility characteristic of round number, and solves the problem in theory about the divisibility characteristic of any round number. 摘要针对整数论中数的整除特征进行了研究，从理论上解决了任意整数的整除特征问题。
A divisibility rule is a shorthand way of determining whether a given number is divisible by a fixed divisor without performing the division, usually by examining its digits. Although there are divisibility tests for numbers in any radix, or base, and they are all different, this article presents rules and examples only for decimal, or base 10, numbers.