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
Eleven is also encountered as a proper name or nickname. For example, in contemporary media the character
In science and chemistry, element 11 is sodium, with the symbol Na. The term eleven is thus