What is the frequency in Hz of a radio wave with an energy of 4.644 times 10 power -24 J per photon?

7.009 x 10^9 Hz

The equation relating the energy of a photon and its frequency is E = h x f.

E = h x f, where E is energy in Joules (J), h is Planck's constant (6.626 x 10^-34 J* s), and f is the frequency in Hz (1/s).

Known
E=4.644 x 10^-24 J/photon
h=6.626 x 10^-34 J*s

Unknown
f

f = E/h =(4.644 x 10^-24 J/photon)/(6.626 x 10^-34 J*s) =7.009 x 10^9/s = 7.009 x 10^9 Hz