If you have a list of names in Numbers it is very difficult to sort by last name unless you have the last name in a separate column. However, you can use a series of formulas to extract the last name and first name, format them properly as Last, First, and then sort them. It will take some extra effort to deal with middle names and initials as well. You can even get rare last names that include spaces to sort properly.
Here is the example file: Presidents.numbers.zip