Alright, let's work through 86841728 times 63402893 step by step
86841728 × 63402893 = 63402893 × (86841728)
+ 63402893 × 8 that equals 507223144
+ 63402893 × 20 which equals 1268057860
+ 63402893 × 700 what gives us 44382025100
+ 63402893 × 1000 yielding 63402893000
+ 63402893 × 40000 yielding 2536115720000
+ 63402893 × 800000 that is equal 50722314400000
+ 63402893 × 6000000 that results in 380417358000000
+ 63402893 × 80000000 what gives us 5072231440000000

= 5506016788319104
