MathDB
Centroamerican Olympiad 2010, problem 1

Source:

May 30, 2010
modular arithmeticnumber theory proposednumber theory

Problem Statement

Denote by S(n)S(n) the sum of the digits of the positive integer nn. Find all the solutions of the equation
n(S(n)āˆ’1)=2010.n(S(n)-1)=2010.