Using Bohr Model Enm = E1(1/m2 - 1/n2) where n is the higher energy level and E1 is the ground state energy of the Hydrogen atom: 13.6 eV or 2.18x10-18Joules. I recommend the Joules for further calculation.
This transition energy is (2.18 x 10-18 J) (1/1662 - 1/1672)
Frequency, f = (E in Joules) / h (h is Plancks Constant in J-s)
and wavelength, λ = c/f where c is the speed of light, 3.00 x 108 m/s
Please consider a tutor. Take care.