But what about integer hashing?

I recently read an article about string hashing which I fell in love with. Also, the episode on Algorithms Live did full justice to the concept. And then there are some awesome articles (or blogs (or forums?)?) on both codechef and codeforces.

But almost each one of them talks about string hashing (with rolling hashes, as in Rabin - Karp, etc) and leaves the rest of the tale for you to unfold. So, I need help. Can someone help me in understanding the concept of hashing integers (with one or two problems based upon them) or say, primes for instance --> after we learn to hash integers :blush: