A 50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons emitted per second by the bulb is x $\times$ 10²⁰. The value of x is __________. [Given : h = 6.63 $\times$ 10^$-$34 Js and c = 3.0 $\times$ 10⁸ ms^$-$1]