Alright, let's work through 87393993 times 19151994 step by step
87393993 × 19151994 = 19151994 × (87393993)
+ 19151994 × 3 which equals 57455982
+ 19151994 × 90 resulting in 1723679460
+ 19151994 × 900 which equals 17236794600
+ 19151994 × 3000 producing 57455982000
+ 19151994 × 90000 yielding 1723679460000
+ 19151994 × 300000 resulting in 5745598200000
+ 19151994 × 7000000 what gives us 134063958000000
+ 19151994 × 80000000 resulting in 1532159520000000

= 1673769229572042
