Friday the 13th is bad luck.
The number 13 is bad luck. Buildings don't have a 13th floor in North America.
There is also a series of horror movies called "Friday the 13th".
In Asia, the number 4 is bad luck, because the word for '4' is the same as the word for 'death'.
Double numbers (like '66' or '88') are lucky in Asia. I think this comes from dice games where double numbers win.
