Alright, let's work through 83448724 times 81513529 step by step
83448724 × 81513529 = 81513529 × (83448724)
+ 81513529 × 4 that results in 326054116
+ 81513529 × 20 which equals 1630270580
+ 81513529 × 700 yielding 57059470300
+ 81513529 × 8000 that equals 652108232000
+ 81513529 × 40000 producing 3260541160000
+ 81513529 × 400000 yielding 32605411600000
+ 81513529 × 3000000 that results in 244540587000000
+ 81513529 × 80000000 that results in 6521082320000000

= 6802199983786996
