No problem, we've got 3992 and 5191 to multiply
3992 × 5191 = 5191 × (3992)
+ 5191 × 2 resulting in 10382
+ 5191 × 90 what gives us 467190
+ 5191 × 900 yielding 4671900
+ 5191 × 3000 resulting in 15573000

= 20722472
