JavaScript and numerical error (rounding)

JavaScript will round numbers that are very large.
Testing in Google Chrome console:

> parseFloat('834343434343434340000')
> 834343434343434300000
expected: 834343434343434340000

The number is bigger than 9e15, and so JavaScript has rounded the number.

more information here:
http://www.hunlock.com/blogs/The_Complete_Javascript_Number_Reference