# Summing in Mathematica.

Gold Member
I want to write down summation of the type
$$\sum_{d|n , d<n}$$ or $$\sum_{d|n}$$ both summing over d.
and d|n means d divides n.

I know that I can use Sum[term, {i, n-1}] but I don't know how to use this condition of divisibility to the summation.
any help?

Thanks.