For example, 7, 222, and 88888 are repdigits in base 10, while is a repdigit in base 7.
In general, a repdigit in base made of repetitions of the digit has value
The repdigits composed by repeated ones are called repunits.
A non-trivial repdigit is a number with at least two digits, however it must be noted that every number can be represented as in base .
The first nontrivial repdigits in base 10 are 11, 22, 33, 44, 55, 66, 77, 88, 99, 111, 222, 333, 444, 555, 666, 777, 888, 999, 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 9999, 11111 more terms