Answers

2015-02-13T15:07:22+05:30
It should be  2^{64}

Let x =  2^{64}

Log x =  log 2^{64}  

Logx = 64(log2)

logx = 64(0.30103)

logx = 19.26592

The characteristic of x is 19
Therefore, there are 20 (19+1) digits in   2^{64}
2 3 2