How is the principal quantum number symbolized?

The principal quantum number is often symbolized by the letter n. However, depending on the context, the principal quantum number can be denoted by other symbols as well.

The principal quantum number is the first of a set of quantum numbers that describe an atomic orbital. These quantum numbers are the principal quantum number, the azimuthal quantum number, the magnetic quantum number and the spin quantum number. They are frequently denoted by the letters n, l, m and s respectively. The principal quantum number can only take positive integer values and is the only quantum number introduced by the Bohr model of the atom.