Excel 2007 has 1,048,576 rows and over 16,384 columns, so you it has a total of 17,179,869,184 cells.
It starts with 3, but can go up to however many sheets you need.
The original version of Excel had a maximum limit of 16,777,216 (16.8 million) cells within a single worksheet and that continued to be the worksheet limit until it was later expanded in version 2007...
more than 1000. you can add as much sheets you want
There are 16,384 columns (A - XFD) and 1,048,576 rows, for a total of 17,179,869,184 cells per worksheet in Excel 2007.