Thirteen

Thirteen is a natural number following twelve and preceding fourteen. It is the smallest number with eight letters in its name in English. In many cultures, the number thirteen is considered unlucky.

In mathematics

Thirteen is the sixth prime number, and the second Wilson prime. It is also a Fibonacci number, a happy number, the third centered square number, and one of only 3 known Wilson primes.

In science

The atomic number of aluminium is thirteen. In the periodic table, it is a member of group 13.

In religion

In Judaism, thirteen signifies the age at which a boy matures and becomes a Bar Mitzvah, i.e., a full member of the Jewish faith. The number 13 is also significant in Christianity, as there were 13 present at the Last Supper.

In popular culture

Thirteen is often considered an unlucky number in many cultures, and is avoided in certain contexts. For example, some buildings do not have a 13th floor, and some airlines do not have a 13th row.

See also

• List of highways numbered 13
• Thirteen (disambiguation)

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