Alright, let's work through 87373954 times 91394378 step by step
87373954 × 91394378 = 91394378 × (87373954)
+ 91394378 × 4 resulting in 365577512
+ 91394378 × 50 that is equal 4569718900
+ 91394378 × 900 that equals 82254940200
+ 91394378 × 3000 yielding 274183134000
+ 91394378 × 70000 resulting in 6397606460000
+ 91394378 × 300000 resulting in 27418313400000
+ 91394378 × 7000000 which equals 639760646000000
+ 91394378 × 80000000 that equals 7311550240000000

= 7985488179230612
