17 (seventeen) is a positive integer following 16 and preceding 18. Its ordinal form is written "17th" or "seventeenth".

Properties Edit

17 is odd prime number. It is the third Fermat prime \(2^{2^2}+1\).

17 is associated with bad luck in Italian superstition.

Ironically, the prize for 2 correct final digits in the German lottery Spiel 77 is equal to 17 euros.

In googology Edit

In Greek-based naming systems, 17 is associated with prefix "heptadeka-", and with prefix "septendeci-" in Latin systems.

17 is the 6th output of the Xi function, \(\Xi(6) = 17\).