Alright, let's work through 81664379 times 23494317 step by step
81664379 × 23494317 = 23494317 × (81664379)
+ 23494317 × 9 resulting in 211448853
+ 23494317 × 70 resulting in 1644602190
+ 23494317 × 300 giving us 7048295100
+ 23494317 × 4000 producing 93977268000
+ 23494317 × 60000 yielding 1409659020000
+ 23494317 × 600000 yielding 14096590200000
+ 23494317 × 1000000 yielding 23494317000000
+ 23494317 × 80000000 what gives us 1879545360000000

= 1918648807834143
