1.8 million x 12.57 =22, 626, 000 lumens
100 watt bulb = 1600 lumens.
22, 626,000/1600 = 14,141
One flare = 14,141 one hundred watt bulbs
(about)
One flare is about the equivalent of a 757's twin nose wheel landing lights. Landing lights are easily visible at 50 miles in desert air...