Alright, let's work through 3985 times 5389 step by step
3985 × 5389 = 5389 × (3985)
+ 5389 × 5 giving us 26945
+ 5389 × 80 that equals 431120
+ 5389 × 900 yielding 4850100
+ 5389 × 3000 which equals 16167000

= 21475165
