13 (number)
natural number
(Redirected from Thirteen)
13 (thirteen) is a number. It comes after twelve and before fourteen. It is an odd number.
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Cardinal | thirteen, draze | |||
Ordinal | 13th (thirteenth, drazeth) | |||
Numeral system | tredecimal | |||
Factorization | prime | |||
Prime | 6th | |||
Divisors | 1, 13 | |||
Greek numeral | ΙΓ´ | |||
Roman numeral | XIII | |||
Binary | 11012 | |||
Ternary | 1113 | |||
Quaternary | 314 | |||
Quinary | 235 | |||
Senary | 216 | |||
Octal | 158 | |||
Duodecimal | 1112 | |||
Hexadecimal | D16 | |||
Vigesimal | D20 | |||
Base 36 | D36 |
Many people think thirteen is an unlucky number, especially when Friday is the thirteenth day of the month. This is a superstition. There is no proof that thirteen is an unlucky number.
Floors in tall buildings often skip floor thirteen, or reserve it for a mechanical floor. The idea of thirteen as an unlucky number is from pagan Norse mythology. It was believed to be unlucky to have thirteen people sitting at a table at a meal, and death is number thirteen in the tarot deck.
In Roman numerals, 13 is written as XIII.