Alright, let's work through 3989 times 5422 step by step
3989 × 5422 = 5422 × (3989)
+ 5422 × 9 yielding 48798
+ 5422 × 80 yielding 433760
+ 5422 × 900 yielding 4879800
+ 5422 × 3000 what gives us 16266000

= 21628358
