Can I track an iphone with the phone number?

My dad left the house last night and he returned at 5am and left again. I don't know where he went. So can I track his iphone with the phone number cause I don't know his icloud info. And I really need to know where he's at I'm worried.

Unfortunately, you can't. Try downloading Find My Friends on your iPhone and his iPhone, and put find my friends in a Utilities folder so he won't notice it. Best of luck!

Of course not, obviously its more secure then that.