The principal quantum number is just the first quantum number out of 5. It actually depends on what value of n. See the attached picture for the ordered arrangement of orbitals. For example, when n=2, we have: 2s2p. Each s holds 1 orbital, p has 3 orbitals, d has 5 orbitals and f has 7 orbitals. So, for n=2, there are 4 total orbitals.