Alright, let's work through 20003890 times 62721372 step by step
20003890 × 62721372 = 62721372 × (20003890)
+ 62721372 × 0 producing 0
+ 62721372 × 90 giving us 5644923480
+ 62721372 × 800 that results in 50177097600
+ 62721372 × 3000 producing 188164116000
+ 62721372 × 00000 giving us 0
+ 62721372 × 000000 producing 0
+ 62721372 × 0000000 resulting in 0
+ 62721372 × 20000000 giving us 1254427440000000

= 1254671426137080
