Alright, let's work through 2663 times 7839 step by step
2663 × 7839 = 7839 × (2663)
+ 7839 × 3 producing 23517
+ 7839 × 60 giving us 470340
+ 7839 × 600 that equals 4703400
+ 7839 × 2000 that is equal 15678000

= 20875257
