Alright, let's work through 84100985 times 80670967 step by step
84100985 × 80670967 = 80670967 × (84100985)
+ 80670967 × 5 that results in 403354835
+ 80670967 × 80 what gives us 6453677360
+ 80670967 × 900 yielding 72603870300
+ 80670967 × 0000 what gives us 0
+ 80670967 × 00000 that is equal 0
+ 80670967 × 100000 what gives us 8067096700000
+ 80670967 × 4000000 what gives us 322683868000000
+ 80670967 × 80000000 that results in 6453677360000000

= 6784507785602495
