is the
natural number following
10 and preceding
12. It is the first number which cannot be represented by a
human counting their eight
fingers and two
thumbs additively. Eleven is the smallest positive integer requiring three syllables in English, and it is also the largest prime number with a single-morpheme name in this language (although etymologically the word
eleven originated from a Germanic compound *
ainlif meaning "one left"
[1]).
Eleven is the 5th smallest
prime number. It is the smallest two-digit prime number in the
decimal base; as well as, of course, in
undecimal (where it is the smallest two-digit number). It is also the smallest three-digit prime in
ternary, and the smallest four-digit prime in
binary, but a single-digit prime in bases larger than eleven, such as
duodecimal,
hexadecimal,
vigesimal and
sexagesimal.
