No factor of a number can be bigger than the square root of that number (excluding the number itself).

That's not correct. For example, three is a factor of six but is greater than its square root.

It is true, however, that you only need to look for factors less than or equal to the square root because, once you have them, the larger factors are easily found by division. For example, once you find that two is a factor of six, simply dividing six by two reveals that three is also a factor.

Edit: That's "six" not "siz"... Thanks BrowserUk!

-sauoq
"My two cents aren't worth a dime.";