No problem, we've got 2121 and 5381 to multiply
2121 × 5381 = 5381 × (2121)
+ 5381 × 1 resulting in 5381
+ 5381 × 20 producing 107620
+ 5381 × 100 giving us 538100
+ 5381 × 2000 producing 10762000

= 11413101
