Alright, let's work through 80379842 times 20915120 step by step
80379842 × 20915120 = 20915120 × (80379842)
+ 20915120 × 2 what gives us 41830240
+ 20915120 × 40 producing 836604800
+ 20915120 × 800 producing 16732096000
+ 20915120 × 9000 resulting in 188236080000
+ 20915120 × 70000 what gives us 1464058400000
+ 20915120 × 300000 resulting in 6274536000000
+ 20915120 × 0000000 giving us 0
+ 20915120 × 80000000 which equals 1673209600000000

= 1681154041011040
