Diviors of zero and invertible elements

If D is a set, then the power set of D is the set P_D of all the subsets of D.

For example, if D = {1,2,3}, the P_D = { 1, 2, 3, (1,2), (1,3), (2,3), (1,2,3) }

Describe the divisors of zero and invertible elements. I'm supposed to do this for all D, but maybe if someone can show how this works with the above D, i will be able to move forward.

Thanks a lot in advance!

That set has no ring structure. What's the definition of sum and multiplication?

My mistake. But i figured the problem out so disregard this post.