Alright, let's work through 81840071 times 15366078 step by step
81840071 × 15366078 = 15366078 × (81840071)
+ 15366078 × 1 that equals 15366078
+ 15366078 × 70 producing 1075625460
+ 15366078 × 000 what gives us 0
+ 15366078 × 0000 what gives us 0
+ 15366078 × 40000 which equals 614643120000
+ 15366078 × 800000 that results in 12292862400000
+ 15366078 × 1000000 resulting in 15366078000000
+ 15366078 × 80000000 that results in 1229286240000000

= 1257560914511538
