A number that is considered unlucky by a lot of cultures, especially Friday the 13th. First, let's get the fact out of the way that it was originally the day on which the Knights Templar were condemned and slaughtered in a pact between the King of France (twat) and the pope (pontificating twat). This effectively disposed all of all opposition to the catholic church (collective twats).
Now, for other interesting 'facts' about the number 13.....
In Tarot decks, the 13th card of the Major Arcana is Death (hooray, he gets his own card)
There were 13 people at the Last Supper of jesus (which is bullshit because Mary got airbrushed out)
13 is considered unlucky as a person can count from 1-12 with their 10 fingers and 2 feet, but not beyond that, so the number 13 is unknown (who came up with this bullshit? they can't count toes then, or their dick or anything else?)
The number 13 was stricken from the clock, because the time 13:37 is hallowed (bit fucked when the 24-hour clock came out then.... beware digital watches, they are the work of the Devil !!!)
Some streets do not contain a house number 13 (especially not ones with less than 12 houses on it as that would be stupid)
Apollo 13 was an unlucky space flight which nearly ended in disaster (had nothing to do with shit planning by NASA at all)
The number of original states in the United States of.... was 13 (now that's fucking unlucky as they needed to expand)
There were 13 Plutonium slugs in 'Fat Man', the atomic bomb dropped on Nagasaki (unlucky if you were anywhere near at the time)
There are traditionally thirteen steps leading up to a gallows (which they no longer have as they were a pain in the neck)
There are 13 full moons in a normal year (which means you have 13 chances to get attacked by a werewolf every year)
Please feel free to add you comments on the number 13 - can be anything you would like, such as, if you rotate 13 90 degrees to the left it looks like eggs on toast, but if you rotate 13 90 degrees to the right it looks like a crap bra....