Alright, let's work through 3902872 times 21052827 step by step
3902872 × 21052827 = 21052827 × (3902872)
+ 21052827 × 2 which equals 42105654
+ 21052827 × 70 that is equal 1473697890
+ 21052827 × 800 which equals 16842261600
+ 21052827 × 2000 giving us 42105654000
+ 21052827 × 00000 producing 0
+ 21052827 × 900000 that is equal 18947544300000
+ 21052827 × 3000000 that results in 63158481000000

= 82166489019144
