Alright, let's work through 81371448 times 19378766 step by step
81371448 × 19378766 = 19378766 × (81371448)
+ 19378766 × 8 what gives us 155030128
+ 19378766 × 40 producing 775150640
+ 19378766 × 400 which equals 7751506400
+ 19378766 × 1000 resulting in 19378766000
+ 19378766 × 70000 what gives us 1356513620000
+ 19378766 × 300000 that equals 5813629800000
+ 19378766 × 1000000 that equals 19378766000000
+ 19378766 × 80000000 giving us 1550301280000000

= 1576878249873168
