By starting with a million and alternatively dividing by 2 and multiplying by 5, Anisha created a sequence of integers that starts 1000000, 500000, 2500000, 1250000, and so on. What is the last integer in her sequence? Express your answer in the form a^b, where a and b are positive integers and a is as small as possible.

qwertyzz Apr 19, 2020