Alright, let's work through 63578917 times 21207821 step by step
63578917 × 21207821 = 21207821 × (63578917)
+ 21207821 × 7 that results in 148454747
+ 21207821 × 10 producing 212078210
+ 21207821 × 900 resulting in 19087038900
+ 21207821 × 8000 yielding 169662568000
+ 21207821 × 70000 yielding 1484547470000
+ 21207821 × 500000 resulting in 10603910500000
+ 21207821 × 3000000 that is equal 63623463000000
+ 21207821 × 60000000 yielding 1272469260000000

= 1348370291109857
