That's right, March 14 is international Pi Day. Get it -- pi is 3.14, and March 14 is 3/14?

Most everyone knows pi -- the ratio of the circumference of a circle to its diameter. But how much do you really know about this magical number? Below are 28 fun facts about pi split up into tidy categories. Enjoy!

Pi in society

Albert Einstein

-Pi Day is also Albert Einstein's birthday, along with the birthdays of Apollo 8 Commander Frank Borman, Astronomer Giovanni Schiaparelli, and last-man-on-the-moon Gene Cernan.

-There is a pi cologne.*

Computing pi

-Computing pi is a stress test for a computer -- a kind of "digital cardiogram.*

-The record for calculating pi, as of 2010, is to 5 trillion digits (source: Gizmodo).

Random pi information

- If you were to print 1 billion decimal values of pi in ordinary font it would stretch from New York City to Kansas (source: Buzzle).

- 3.14 backwards looks like PIE.

- "I prefer pi" is a palindrome.