Alright, let's work through 13356643 times 6421764 step by step
13356643 × 6421764 = 6421764 × (13356643)
+ 6421764 × 3 resulting in 19265292
+ 6421764 × 40 that results in 256870560
+ 6421764 × 600 giving us 3853058400
+ 6421764 × 6000 resulting in 38530584000
+ 6421764 × 50000 that is equal 321088200000
+ 6421764 × 300000 which equals 1926529200000
+ 6421764 × 3000000 yielding 19265292000000
+ 6421764 × 10000000 yielding 64217640000000

= 85773209178252
