But you're using two 32-bit numbers, which have the same total bits as a 64-bit number. There are equally many 32-bit x 32-bit pairs as there are 64-bit numbers.
But you're using two 32-bit numbers, which have the same total bits as a 64-bit number. There are equally many 32-bit x 32-bit pairs as there are 64-bit numbers.
And there are as many pairs of numbers between 1-8 and numbers from 1-64, but it's still pretty apparent that most of them are not represented in the set of products.