According to Stefan's law of radiation, a black body radiates...

According to Stefan's law of radiation, a black body radiates energy σT⁴ from its unit surface area every second, where T is the surface temperature of the black body. A nuclear weapon may be thought of as a ball of radius 0.5 m. When detonated, it reaches a temperature of 10⁶ K and can be treated as a black body. Estimate the power it radiates.