kids encyclopedia robot

13 (number) facts for kids

Kids Encyclopedia Facts
Quick facts for kids
12 13 14
Cardinal thirteen
Ordinal 13th
Numeral system tredecimal
Factorization prime
Prime 6th
Divisors 1, 13
Roman numeral XIII
Binary 11012
Ternary 1113
Quaternary 314
Quinary 235
Senary 216
Octal 158
Duodecimal 1112
Hexadecimal D16
Vigesimal D20
Base 36 D36

Thirteen is a number. It comes after twelve and before fourteen. It is an odd number.

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.

Related pages

kids search engine
13 (number) Facts for Kids. Kiddle Encyclopedia.