Alright, let's work through 21248135 times 64936221 step by step
21248135 × 64936221 = 64936221 × (21248135)
+ 64936221 × 5 that results in 324681105
+ 64936221 × 30 that is equal 1948086630
+ 64936221 × 100 that results in 6493622100
+ 64936221 × 8000 resulting in 519489768000
+ 64936221 × 40000 resulting in 2597448840000
+ 64936221 × 200000 resulting in 12987244200000
+ 64936221 × 1000000 resulting in 64936221000000
+ 64936221 × 20000000 that results in 1298724420000000

= 1379773590197835
