Alright, let's work through 81214813 times 78683255 step by step
81214813 × 78683255 = 78683255 × (81214813)
+ 78683255 × 3 yielding 236049765
+ 78683255 × 10 producing 786832550
+ 78683255 × 800 that equals 62946604000
+ 78683255 × 4000 giving us 314733020000
+ 78683255 × 10000 that is equal 786832550000
+ 78683255 × 200000 what gives us 15736651000000
+ 78683255 × 1000000 producing 78683255000000
+ 78683255 × 80000000 giving us 6294660400000000

= 6390245841056315
