Find sum of digits of:(1999)^1999.
[The final answer should be a single digit number, for example, (2)^16 = 65536 and the sum of its digits will be given by (6 + 5 + 5 + 3 + 6 = 25, which again will be reduced to 2 + 5 = 7].

(In reply to re: super easy by SilverKnight)

http://mathforum.org/library/drmath/sets/select/dm_mod.html

Posted by Richard on 2004-01-27 12:03:26