Answer Submission Is Not Available
many thanks to all of you for your effort and your solutions.
The first to send the correct solution were Alexander Pappas, King James, David Sullivan and Christian Bedat.
Again, many thanks
and hope to hear from you soon.
Here is the solution of the January 2016 problem:
2172 x 5170 =4x10170 = 40000000….00000.
The sum of the digits is a 4.