1. The problem statement, all variables and given/known data Let X=10000000099 represent an eleven digit no. and let Y be a four digit no. which divides X.Find the sum of the digits of the four digit no. Y. 2. Relevant equations None 3. The attempt at a solution I guess I have to factorize X. But it is really difficult to do so as i cant find a prime which divides it. Moreover i am in search for a systematic solution and not any trial method.Any help in this regard would be sincerely appreciated. Thank You.