Alright, let's work through 2112 times 2639 step by step
2112 × 2639 = 2639 × (2112)
+ 2639 × 2 yielding 5278
+ 2639 × 10 giving us 26390
+ 2639 × 100 that equals 263900
+ 2639 × 2000 that is equal 5278000

= 5573568
