Alright, let's work through 40020839 times 93778907 step by step
40020839 × 93778907 = 93778907 × (40020839)
+ 93778907 × 9 that is equal 844010163
+ 93778907 × 30 that equals 2813367210
+ 93778907 × 800 which equals 75023125600
+ 93778907 × 0000 what gives us 0
+ 93778907 × 20000 that results in 1875578140000
+ 93778907 × 000000 giving us 0
+ 93778907 × 0000000 which equals 0
+ 93778907 × 40000000 yielding 3751156280000000

= 3753110538642973
