Alright, let's work through 64521217 times 20000372 step by step
64521217 × 20000372 = 20000372 × (64521217)
+ 20000372 × 7 what gives us 140002604
+ 20000372 × 10 that equals 200003720
+ 20000372 × 200 what gives us 4000074400
+ 20000372 × 1000 giving us 20000372000
+ 20000372 × 20000 that equals 400007440000
+ 20000372 × 500000 what gives us 10000186000000
+ 20000372 × 4000000 producing 80001488000000
+ 20000372 × 60000000 that equals 1200022320000000

= 1290448341892724
