No problem, we've got 3309 and 6391 to multiply
3309 × 6391 = 6391 × (3309)
+ 6391 × 9 that results in 57519
+ 6391 × 00 that results in 0
+ 6391 × 300 that results in 1917300
+ 6391 × 3000 resulting in 19173000

= 21147819
