Alright, let's work through 87400397 times 58978658 step by step
87400397 × 58978658 = 58978658 × (87400397)
+ 58978658 × 7 which equals 412850606
+ 58978658 × 90 giving us 5308079220
+ 58978658 × 300 producing 17693597400
+ 58978658 × 0000 yielding 0
+ 58978658 × 00000 yielding 0
+ 58978658 × 400000 yielding 23591463200000
+ 58978658 × 7000000 resulting in 412850606000000
+ 58978658 × 80000000 giving us 4718292640000000

= 5154758123727226
