Alright, let's work through 78800813 times 21723453 step by step
78800813 × 21723453 = 21723453 × (78800813)
+ 21723453 × 3 giving us 65170359
+ 21723453 × 10 giving us 217234530
+ 21723453 × 800 which equals 17378762400
+ 21723453 × 0000 producing 0
+ 21723453 × 00000 that equals 0
+ 21723453 × 800000 giving us 17378762400000
+ 21723453 × 8000000 giving us 173787624000000
+ 21723453 × 70000000 that results in 1520641710000000

= 1711825757567289
