Alright, let's work through 81609699 times 49890268 step by step
81609699 × 49890268 = 49890268 × (81609699)
+ 49890268 × 9 that is equal 449012412
+ 49890268 × 90 that equals 4490124120
+ 49890268 × 600 yielding 29934160800
+ 49890268 × 9000 that equals 449012412000
+ 49890268 × 00000 giving us 0
+ 49890268 × 600000 yielding 29934160800000
+ 49890268 × 1000000 which equals 49890268000000
+ 49890268 × 80000000 giving us 3991221440000000

= 4071529754509332
