Alright, let's work through 3996 times 5439 step by step
3996 × 5439 = 5439 × (3996)
+ 5439 × 6 that is equal 32634
+ 5439 × 90 that equals 489510
+ 5439 × 900 that is equal 4895100
+ 5439 × 3000 producing 16317000

= 21734244
