| ||||
|---|---|---|---|---|
| Cardinal | thirteen | |||
| Ordinal | 13th (thirteenth) | |||
| Numeral system | tredecimal | |||
| Factorization | prime | |||
| Prime | 6th | |||
| Divisors | 1, 13 | |||
| Greek numeral | ΙΓ´ | |||
| Roman numeral | XIII | |||
| Binary | 11012 | |||
| Ternary | 1113 | |||
| Senary | 216 | |||
| Octal | 158 | |||
| Duodecimal | 1112 | |||
| Hexadecimal | D16 | |||
| Hebrew numeral | י"ג | |||
| Babylonian numeral | 𒌋𒐗 | |||
13 (thirteen) is the natural number following 12 and preceding 14.
Folklore surrounding the number 13 appears in many cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month). This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition.[1]