How much is 6 trillion times 13.1billion?

Answer 1

Answer is 78,600,000,000,000,000,000,000,000.

Writing too many zeros can be tedious and confusing, so writing the numbers in terms of base and exponent is better:

(6 x 1012) x (13.1 x 109) = 78.6 x 1021 = 786 x 1020