Alright, let's work through 81763675 times 83986885 step by step
81763675 × 83986885 = 83986885 × (81763675)
+ 83986885 × 5 giving us 419934425
+ 83986885 × 70 giving us 5879081950
+ 83986885 × 600 that results in 50392131000
+ 83986885 × 3000 giving us 251960655000
+ 83986885 × 60000 giving us 5039213100000
+ 83986885 × 700000 yielding 58790819500000
+ 83986885 × 1000000 that results in 83986885000000
+ 83986885 × 80000000 what gives us 6718950800000000

= 6867076369402375
