12-19-2018, 08:54 PM
Given a random positive integer N, compute the sum S of its digits (for example 50 -> S = 5 + 0 = 5). Subtract this sum from N, thus getting the result "R=N-S".
What is the smallest divisor greater than 1 that can divide evenly every R so computed? Why is it so?
What is the smallest divisor greater than 1 that can divide evenly every R so computed? Why is it so?