 <p>That's a floating point number. Unlike any other language I've ever encountered, <em>all</em> numbers in Javascript are actually 64-bit floating numbers. Technically, there are no native integers in Javascript. See <a href="http://www.hunlock.com/blogs/The_Complete_Javascript_Number_Reference" rel="nofollow noreferrer">The Complete Javascript Number Reference</a> for the full ugly story.</p>