Alright, let's work through 80671056 times 63674863 step by step
80671056 × 63674863 = 63674863 × (80671056)
+ 63674863 × 6 what gives us 382049178
+ 63674863 × 50 yielding 3183743150
+ 63674863 × 000 that equals 0
+ 63674863 × 1000 giving us 63674863000
+ 63674863 × 70000 yielding 4457240410000
+ 63674863 × 600000 giving us 38204917800000
+ 63674863 × 0000000 that is equal 0
+ 63674863 × 80000000 producing 5093989040000000

= 5136718438865328
