Problem-16(Power digit sum)

2¹⁵ = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 2¹⁰⁰⁰?

Solution Trick:

The logic goes to childhood multiplication process. What can we do when we want to multiply a big number a( such as a=9999999999999) by a number b (such as b=2 ) . We continuously multiply the rightmost digit of a by b until we reach the leftmost digit of a.

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