What is the billionth prime number? The answer on this question and a lot of other things worth knowing in the area of Prime Numbers can you find here.
Playing around with and discovering of larger Prime Numbers up to 1019
The Schönhage Strassen Algorithm (SSA) is an algorithm to multiply big numbers very fast. An explanation of SSA and a sample program in C++ can you find here.
Modular arithmetic is arithmetic with residues. A description of Modular arithmetic and the Montgomery multiplication.
A description of LBA (Long Binary Architecture); an architecture for arithmetic with large numbers in an assembler program or a C++ program.