Alright, let's work through 21437280 times 51426731 step by step
21437280 × 51426731 = 51426731 × (21437280)
+ 51426731 × 0 what gives us 0
+ 51426731 × 80 yielding 4114138480
+ 51426731 × 200 resulting in 10285346200
+ 51426731 × 7000 producing 359987117000
+ 51426731 × 30000 giving us 1542801930000
+ 51426731 × 400000 producing 20570692400000
+ 51426731 × 1000000 that results in 51426731000000
+ 51426731 × 20000000 what gives us 1028534620000000

= 1102449231931680
