How many positive integers smaller than 1,000,000 are powers of 2, but are not powers of 4? You may find it useful to consider that 2^10 = 1024.

Guest Dec 22, 2021

#1**+1 **

A power of 4 is simply 2^(even integer). We must thus avoid even powers of 2.

Since 2^10 = 1024, (2^10)^2 = 2^20 is a bit larger than 1,000,000. Thus, 2^19 will probably be the largest power of 2 less than 1,000,000.

We then count all the odd numbers from 19 to 1, which accounts for **10 numbers.**

*See https://web2.0calc.com/questions/help-please_50938 for more information.*

tinfoilhat Dec 22, 2021