Alright, let's work through 21042916 times 30608740 step by step
21042916 × 30608740 = 30608740 × (21042916)
+ 30608740 × 6 that is equal 183652440
+ 30608740 × 10 that equals 306087400
+ 30608740 × 900 what gives us 27547866000
+ 30608740 × 2000 that equals 61217480000
+ 30608740 × 40000 that equals 1224349600000
+ 30608740 × 000000 what gives us 0
+ 30608740 × 1000000 that results in 30608740000000
+ 30608740 × 20000000 giving us 612174800000000

= 644097144685840
