20

This number is a composite.

Single Curio View: (Seek other curios for this number)

Reversal(1^20 + 2^20 + ... + 20^20) is prime. Reversal(20) is the only other known number with this property. [Firoozbakht]

Submitted: 2010-07-18 13:58:17; Last Modified: 2020-06-14 03:29:53.