Alright, let's work through 63506903 times 73638420 step by step
63506903 × 73638420 = 73638420 × (63506903)
+ 73638420 × 3 yielding 220915260
+ 73638420 × 00 that results in 0
+ 73638420 × 900 yielding 66274578000
+ 73638420 × 6000 resulting in 441830520000
+ 73638420 × 00000 that results in 0
+ 73638420 × 500000 that equals 36819210000000
+ 73638420 × 3000000 producing 220915260000000
+ 73638420 × 60000000 that results in 4418305200000000

= 4676547996013260
