DivisorSum[n, form]
represents the sum of for all i that divide n.

DivisorSum[n, form, cond]
includes only those divisors for which gives True.


  • n can be symbolic or a positive integer.
  • form and cond must be Function objects.
  • DivisorSum[n, form] is equivalent to Sum[form[d], {d, Divisors[n]}] for positive n.
  • DivisorSum[n, form, cond] is automatically simplified when n is a positive integer.
  • DivisorSum[n, form] is automatically simplified when form is a polynomial function.
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