Eleven

Eleven is the natural number that follows ten and precedes twelve. In base-10 notation it is written as 11. It is a prime number and the smallest two-digit prime; it is also the fifth prime overall. In various numeral systems it appears as binary 1011 and hexadecimal B, and in Roman numerals XI.

Eleven is used in ordinal form as eleventh. In calendars and dates, the eleventh day and the eleventh month exist in calendars that use day-month-year formats. The term also appears in phrases such as the eleventh hour, meaning at the last possible moment. In team sports such as football (soccer) and cricket, eleven or the eleven refers to the standard number of players on a team.

Eleven is also encountered as a proper name or nickname. For example, in contemporary media the character Eleven (often called El) from the TV series Stranger Things is portrayed as a young girl with telekinetic abilities. The word is sometimes used as a given name or stage name in other works of fiction.

In science and chemistry, element 11 is sodium, with the symbol Na. The term eleven is thus connected to a range of mathematical, linguistic, cultural, and scientific contexts.