This article is good for more information about this topic: http://en.wikipedia.org/wiki/Integer_(computer_science)
So the answer to the question should be:
From -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807,
or from −(2^63) to 2^63 − 1
The highest positive number stored in a signed int is represented binary as
—– 63 ones —–
0111111111111111111111111111111111111111111111111111111111111111
If you think carefully you can find out that this number is exactly 2^63 – 1.