Alright, let's work through 8139 times 2628 step by step
8139 × 2628 = 2628 × (8139)
+ 2628 × 9 that equals 23652
+ 2628 × 30 that is equal 78840
+ 2628 × 100 that results in 262800
+ 2628 × 8000 yielding 21024000

= 21389292
