35452...35943 (23-digits)

This number is a prime.

                                                   354 5259010403 1691935943

The largest prime narcissistic number, i.e., a number such that the sum of each digit raised to a power equal to the length of the number equals the number. Numbers with this property are sometimes known as Armstrong numbers or Pluperfect Digital Invariants (PPDI's). [De Geest]