I believe Facebook now limits the number of friends anyone can have on their Facebook timelines to no more than 5,000. You may be able to convert your personal account to a Page and then you are not limited to 5,000. There are quite a few people who have 5,000 friends and a lot of these are celebrities like Shakira, Eminem, and Rihanna.
However, it is interesting to note that a scientist by the name of Robin Dunbar, has a theory that only a maximum of 150 friendships can be handled by a part of the human brain known as the neocortex.