No problem, we've got 21355452 and 20855367 to multiply
21355452 × 20855367 = 20855367 × (21355452)
+ 20855367 × 2 which equals 41710734
+ 20855367 × 50 that results in 1042768350
+ 20855367 × 400 what gives us 8342146800
+ 20855367 × 5000 that results in 104276835000
+ 20855367 × 50000 resulting in 1042768350000
+ 20855367 × 300000 what gives us 6256610100000
+ 20855367 × 1000000 resulting in 20855367000000
+ 20855367 × 20000000 resulting in 417107340000000

= 445375788910884
