13 (thirteen) is a positive integer following 12 and preceding 14. Its ordinal form is written "13th" or "thirteenth".

Properties Edit

13 is an odd prime number.

A set of 13 objects is sometimes called a baker's dozen.

13 is the fourth busy beaver number \(\Sigma(4) = 13\), the largest known value of the function. \(\Sigma(5)\) is known to be at least \(4098\).

13 is associated with bad luck in Western superstition.

In googologyEdit

In Greek-based naming systems, 13 is associated with prefix "trideka-", and with prefix "tredeci-" in Latin systems.

13 is the current lower bound for the mathematical problem where Graham's number arose.

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.