Alright, let's work through 28639707 times 56783872 step by step
28639707 × 56783872 = 56783872 × (28639707)
+ 56783872 × 7 which equals 397487104
+ 56783872 × 00 what gives us 0
+ 56783872 × 700 resulting in 39748710400
+ 56783872 × 9000 producing 511054848000
+ 56783872 × 30000 that results in 1703516160000
+ 56783872 × 600000 yielding 34070323200000
+ 56783872 × 8000000 that results in 454270976000000
+ 56783872 × 20000000 yielding 1135677440000000

= 1626273456405504
