Lenny Conundrum #226?

Question

A digital sum of a number is found by adding all of the digits of a number, then adding all the digits of that number, and so on, until you are left with a one-digit number.

For example, the digital sum of the number 729 would be found like this: 7+2+ 9 = 18, and then 1+ 8 = 9.

What is the digital sum of the number that can be found by the following formula?

(962773 + 2)83721

Answer 1

9 is the answer

83721 is divisible by 9 so (962773 + 2)83721 is also divisible by 9. If A number is divisible by 9 then the digit sum is 9.