Alright, let's work through 21248864 times 81918490 step by step
21248864 × 81918490 = 81918490 × (21248864)
+ 81918490 × 4 yielding 327673960
+ 81918490 × 60 giving us 4915109400
+ 81918490 × 800 which equals 65534792000
+ 81918490 × 8000 which equals 655347920000
+ 81918490 × 40000 resulting in 3276739600000
+ 81918490 × 200000 that equals 16383698000000
+ 81918490 × 1000000 that equals 81918490000000
+ 81918490 × 20000000 yielding 1638369800000000

= 1740674853095360
