Prime Factors Calculator

This calculator will calculate the prime factors of a positive integer. The algorithm used can, in theory, handle very large numbers but beware that numbers with large prime factors could take a long time to factorise. For example, 1234567890123456789012345678901234567890 factorises almost instantly, whereas 12345678901234567 takes a lot longer, because, even though smaller, one of the prime factors is a large number.