Positive integer $m$ is such that the sum of decimal digits of $8^m$ equals 8. Can the last digit of $8^m$ be equal 6? (Author: V. Senderov) (compare with http://www.artofproblemsolving.com/Forum/viewtopic.php?f=57&t=431860)
Problem
Source: Problem 6 of Russian Regional Olympiad 2009 Grade 9
Tags: number theory proposed, number theory