Alright, let's work through 21378705 times 91165123 step by step
21378705 × 91165123 = 91165123 × (21378705)
+ 91165123 × 5 which equals 455825615
+ 91165123 × 00 which equals 0
+ 91165123 × 700 giving us 63815586100
+ 91165123 × 8000 producing 729320984000
+ 91165123 × 70000 that results in 6381558610000
+ 91165123 × 300000 yielding 27349536900000
+ 91165123 × 1000000 giving us 91165123000000
+ 91165123 × 20000000 that is equal 1823302460000000

= 1948992270905715
