Alright, let's work through 18689792 times 72289123 step by step
18689792 × 72289123 = 72289123 × (18689792)
+ 72289123 × 2 giving us 144578246
+ 72289123 × 90 what gives us 6506021070
+ 72289123 × 700 that is equal 50602386100
+ 72289123 × 9000 producing 650602107000
+ 72289123 × 80000 that is equal 5783129840000
+ 72289123 × 600000 resulting in 43373473800000
+ 72289123 × 8000000 resulting in 578312984000000
+ 72289123 × 10000000 that is equal 722891230000000

= 1351068672732416
