DivisorSigma[k, n] gives the divisor function \[Sigma]_k (n).

Some integer functions. The remainder on dividing 17 by 3. The integer part of 17/3.

DirichletConvolve[f, g, n, m] gives the Dirichlet convolution of the expressions f and g.

Unicode: 03C3. Aliases: Esc s Esc, Esc sigma Esc. Greek letter. Used in TraditionalForm for DivisorSigma and WeierstrassSigma.

Building on its broad algorithmic and mathematical capabilities, Mathematica provides a unique level of highly general and efficient support for additive number theory.

Divisors[n] gives a list of the integers that divide n.

Building on its broad strengths in mathematics in general, and in special functions in particular, Mathematica provides a unique level of support for multiplicative number ...

Mathematica contains the world's largest collection of number theoretic functions, many based on specially developed algorithms.

Building on its broad strengths in mathematics in general, and in special functions in particular, Mathematica provides a unique level of support for analytic number theory, ...

DivisorSum[n, form] represents the sum of form[i] for all i that divide n. DivisorSum[n, form, cond] includes only those divisors for which cond[i] gives True.