Alright, let's work through 84521690 times 21001950 step by step
84521690 × 21001950 = 21001950 × (84521690)
+ 21001950 × 0 yielding 0
+ 21001950 × 90 resulting in 1890175500
+ 21001950 × 600 which equals 12601170000
+ 21001950 × 1000 resulting in 21001950000
+ 21001950 × 20000 producing 420039000000
+ 21001950 × 500000 that results in 10500975000000
+ 21001950 × 4000000 producing 84007800000000
+ 21001950 × 80000000 that results in 1680156000000000

= 1775120307295500
