111 (one hundred [and] eleven) is the natural number following 110 and preceding 112.
In mathematics
111 is the fourth non-trivial nonagonal number, and the seventh perfect totient number.
111 is furthermore the ninth number such that its Euler totient <math>\varphi(n)</math> of 72 is equal to the totient value of its sum-of-divisors:
:<math>\varphi(111) = \varphi(\sigma(111)).</math>
Two other of its multiples (333 and 555) also have the same property (with totients of 216 and 288, respectively).