123 (number)
123 is the natural number following 122 and preceding 124.
In mathematics
- 123 is a Lucas number. It is the eleventh member of the Mian–Chowla sequence.
- Along with 6, 123 is one of only two positive integers that is simultaneously two more than a perfect square and two less than a perfect cube.
- 123 is the first whole number containing numbers from 1 to 3.