Determine the number of photons:

A certain photon detector receives a signal of total energy 4.05*10^18 Joules from radiation of wavelength 535.00nm.

(The only equation I can think to use is E(energy)= 6.63*10^-34 * (C(speed of light) / wavelength, but after I solve for speed of light how to I get the number of photons?)

No No NO.

Use that equation to solve for ENERGY in each photon.

Then,
signal energy=energyinPhoton*numbphotons
solve fornumbphotons