MathDB

9.6

Part of 2009 All-Russian Olympiad Regional Round

Problems(1)

Last digit of a power of 8

Source: Problem 6 of Russian Regional Olympiad 2009 Grade 9

9/19/2011
Positive integer mm is such that the sum of decimal digits of 8m8^m equals 8. Can the last digit of 8m8^m be equal 6?
(Author: V. Senderov)
(compare with http://www.artofproblemsolving.com/Forum/viewtopic.php?f=57&t=431860)
number theory proposednumber theory