Alright, let's work through 21041862 times 99803436 step by step
21041862 × 99803436 = 99803436 × (21041862)
+ 99803436 × 2 yielding 199606872
+ 99803436 × 60 which equals 5988206160
+ 99803436 × 800 resulting in 79842748800
+ 99803436 × 1000 resulting in 99803436000
+ 99803436 × 40000 yielding 3992137440000
+ 99803436 × 000000 which equals 0
+ 99803436 × 1000000 that equals 99803436000000
+ 99803436 × 20000000 producing 1996068720000000

= 2100050127437832
