Did you know that if you write out pi to two decimal places, backwards it spells "pie"?

Here's this weeks math contest! Enter for a chance to win, open until next Thursday or until two winners have been declared. Have fun!

What is the smallest positive prime integer that is

nota factor of 1x2x3x4x5x6x7x8x9x10x11x12x13x14x15x16x17x18x19x20?

RULES

- No giving the answer to somebody else. Be honest about this, please!
- Explain your answer! I will not give you the prize if you can't explain how you arrived at your answer.
- Submit your own response. This means you can't do a "two for one" deal.
- Have fun! The prizes are really lit, so even if you don't know the answer, just try.