Alright, let's work through 81989813 times 39613409 step by step
81989813 × 39613409 = 39613409 × (81989813)
+ 39613409 × 3 what gives us 118840227
+ 39613409 × 10 resulting in 396134090
+ 39613409 × 800 giving us 31690727200
+ 39613409 × 9000 which equals 356520681000
+ 39613409 × 80000 that equals 3169072720000
+ 39613409 × 900000 that equals 35652068100000
+ 39613409 × 1000000 that results in 39613409000000
+ 39613409 × 80000000 which equals 3169072720000000

= 3247895996202517
