Alright, let's work through 84542734 times 89674009 step by step
84542734 × 89674009 = 89674009 × (84542734)
+ 89674009 × 4 what gives us 358696036
+ 89674009 × 30 what gives us 2690220270
+ 89674009 × 700 giving us 62771806300
+ 89674009 × 2000 that results in 179348018000
+ 89674009 × 40000 that is equal 3586960360000
+ 89674009 × 500000 that results in 44837004500000
+ 89674009 × 4000000 giving us 358696036000000
+ 89674009 × 80000000 giving us 7173920720000000

= 7581285889600606
