Alright, let's work through 20791961 times 40011604 step by step
20791961 × 40011604 = 40011604 × (20791961)
+ 40011604 × 1 that results in 40011604
+ 40011604 × 60 what gives us 2400696240
+ 40011604 × 900 which equals 36010443600
+ 40011604 × 1000 producing 40011604000
+ 40011604 × 90000 what gives us 3601044360000
+ 40011604 × 700000 yielding 28008122800000
+ 40011604 × 0000000 producing 0
+ 40011604 × 20000000 that results in 800232080000000

= 831919709915444
