There are a few different areas of philosophy and it's useful to separate them out:

1) Logic (this is useful and also can be called maths) 2) Political Philosophy / Political Theory (crosses over with politics/history, again useful) 3) Ethics (useful and important but not necessarily worth academic study) 4) History of Philosophy (this is really the history of thought and useful and interesting. A lot of philosophy is really this) but unfortunately it blurs into attempting new thought 5) epistemology (useless, science is the better path)

Source: I studied philosophy.

It's important to remember that early philosophers tended to also be mathematicians and scientists.