Want to test if a huge number is a prime number? Try it below...

The input can be arbitrarily large numbers. However, it's not a good idea to stress your computer too much... Actually, the applet works in a brute-force manner. There is no known method for this operation; and it's widely believed that there doesn't exist such a method. If you happen to find one, its meaning is far beyond enhancing a Thinkquest webpage. In fact, the commonly used RSA encryption algorithm works on the idea that multiplication of huge prime numbers is an irreversible operation. If you can prove that wrong... you know what you can do.

On my laptop, dealing with numbers involving prime factors with 10-digits or less works within reasonable time. Beyond that... well... your COMPUTER is on its own...