Alright, let's work through 21067698 times 15315991 step by step
21067698 × 15315991 = 15315991 × (21067698)
+ 15315991 × 8 yielding 122527928
+ 15315991 × 90 producing 1378439190
+ 15315991 × 600 that is equal 9189594600
+ 15315991 × 7000 what gives us 107211937000
+ 15315991 × 60000 that is equal 918959460000
+ 15315991 × 000000 that is equal 0
+ 15315991 × 1000000 yielding 15315991000000
+ 15315991 × 20000000 giving us 306319820000000

= 322672672958718
