Alright, let's work through 39777800 times 99071643 step by step
39777800 × 99071643 = 99071643 × (39777800)
+ 99071643 × 0 that results in 0
+ 99071643 × 00 what gives us 0
+ 99071643 × 800 yielding 79257314400
+ 99071643 × 7000 that results in 693501501000
+ 99071643 × 70000 that equals 6935015010000
+ 99071643 × 700000 producing 69350150100000
+ 99071643 × 9000000 resulting in 891644787000000
+ 99071643 × 30000000 that results in 2972149290000000

= 3940852000925400
