Well, if by "both" you mean something like "Chapter 1: The Beginning," then yes, you can do both. In fact when chapters have titles, they usually have a number too.
However, if you mean alternating numbered chapters with titled chapters (e. g., Chapter 1, Chapter 2, Chapter 3: The Meeting, Chapter 4, Chapter 5: Something Else Happens, etc.), then it might get kind of messy.
But that's just my opinion. I believe in consistency. All numbers, all titles, or all numbers and titles, not a mix. *shrug*