Alright, let's work through 77043651 times 39966401 step by step
77043651 × 39966401 = 39966401 × (77043651)
+ 39966401 × 1 that results in 39966401
+ 39966401 × 50 which equals 1998320050
+ 39966401 × 600 what gives us 23979840600
+ 39966401 × 3000 what gives us 119899203000
+ 39966401 × 40000 resulting in 1598656040000
+ 39966401 × 000000 that is equal 0
+ 39966401 × 7000000 yielding 279764807000000
+ 39966401 × 70000000 resulting in 2797648070000000

= 3079157450370051
