Alright, let's work through 42039587 times 84257840 step by step
42039587 × 84257840 = 84257840 × (42039587)
+ 84257840 × 7 producing 589804880
+ 84257840 × 80 that equals 6740627200
+ 84257840 × 500 producing 42128920000
+ 84257840 × 9000 that results in 758320560000
+ 84257840 × 30000 which equals 2527735200000
+ 84257840 × 000000 what gives us 0
+ 84257840 × 2000000 that is equal 168515680000000
+ 84257840 × 40000000 what gives us 3370313600000000

= 3542164795112080
