Alright, let's work through 12639834 times 89850879 step by step
12639834 × 89850879 = 89850879 × (12639834)
+ 89850879 × 4 resulting in 359403516
+ 89850879 × 30 that is equal 2695526370
+ 89850879 × 800 which equals 71880703200
+ 89850879 × 9000 resulting in 808657911000
+ 89850879 × 30000 yielding 2695526370000
+ 89850879 × 600000 resulting in 53910527400000
+ 89850879 × 2000000 giving us 179701758000000
+ 89850879 × 10000000 that is equal 898508790000000

= 1135700195314086
