Alright, let's work through 80964390 times 78525736 step by step
80964390 × 78525736 = 78525736 × (80964390)
+ 78525736 × 0 which equals 0
+ 78525736 × 90 which equals 7067316240
+ 78525736 × 300 which equals 23557720800
+ 78525736 × 4000 what gives us 314102944000
+ 78525736 × 60000 producing 4711544160000
+ 78525736 × 900000 that results in 70673162400000
+ 78525736 × 0000000 that equals 0
+ 78525736 × 80000000 which equals 6282058880000000

= 6357788314541040
