Vikki is quite correct. The song is just a bit over two octaves in range....No big deal...any half decent singer should cope with such a range providing it is either originally set in an appropriate key or transposed to a more suitable key. Here is an article explaining vocal ranges.
http://www.vocalist.org.uk/vocal_range_key.html
And here is an article explaining octaves and how piano notes are named.
http://www.vocalist.org.uk/vocal_range_key.html