Alright, let's work through 80872679 times 21707609 step by step
80872679 × 21707609 = 21707609 × (80872679)
+ 21707609 × 9 that equals 195368481
+ 21707609 × 70 resulting in 1519532630
+ 21707609 × 600 that is equal 13024565400
+ 21707609 × 2000 yielding 43415218000
+ 21707609 × 70000 that equals 1519532630000
+ 21707609 × 800000 that results in 17366087200000
+ 21707609 × 0000000 which equals 0
+ 21707609 × 80000000 resulting in 1736608720000000

= 1755552494514511
