Alright, let's work through 20400765 times 12843907 step by step
20400765 × 12843907 = 12843907 × (20400765)
+ 12843907 × 5 what gives us 64219535
+ 12843907 × 60 that equals 770634420
+ 12843907 × 700 that equals 8990734900
+ 12843907 × 0000 yielding 0
+ 12843907 × 00000 that results in 0
+ 12843907 × 400000 what gives us 5137562800000
+ 12843907 × 0000000 that is equal 0
+ 12843907 × 20000000 yielding 256878140000000

= 262025528388855
