If the work function of a metal is 6.63 $\times$ 10^$-$19J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ____________ nm. (Nearest integer)

[Given : h = 6.63 $\times$ 10^$-$34 J s, and c = 3 $\times$ 10⁸ m s^$-$1]