In other words, an X bit number is X 1's and 0's to create a binary number. So 1024 bits is 1024 1s and 0s making a possibly very large number.

To use numbers like this, it requires pushing a lot of bits onto a stack. Basically, you maloc 1024 bits, then fill that space. To determine if that number is prime.... well, seach google for determining large prime numbers because its a pain to try to explain.

Although..... if you have 1022 0's followed by two 1s (00000......00000011) you would have a 1024 bit prime number, although the number would be 3