数字和








一个整数的数字和，是把它的所有数字相加起来所得的和。例如，84001的数字和是8+4+0+0+1 = 13。


这个概念与數字根有密切的关系，但并不相同，数字根是把所有数字相加起来所得的和，然后再把这个和的所有数字相加起来，又得到一个和，重复这个步骤，直到最终只剩下一个数字，这个数字便称为数字根。数字和可以是任意的值，而数字根只能是1到9。


数字和可以用来判断一个数是否能被3或9整除。如果数字和能被3或9整除，则原来的数也能被3或9整除。可參照去九法、整除規則。



外部链接



  • 埃里克·韦斯坦因. Digit Sum. MathWorld. 


  • 整数数列线上大全中的数列（OEIS中的数列A007953）



Nuvola apps edu mathematics-p.svg  這是與数论相關的小作品。你可以通过编辑或修订扩充其内容。






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