Alright, let's work through 64708080 times 78235535 step by step
64708080 × 78235535 = 78235535 × (64708080)
+ 78235535 × 0 that results in 0
+ 78235535 × 80 that equals 6258842800
+ 78235535 × 000 that equals 0
+ 78235535 × 8000 giving us 625884280000
+ 78235535 × 00000 producing 0
+ 78235535 × 700000 resulting in 54764874500000
+ 78235535 × 4000000 that equals 312942140000000
+ 78235535 × 60000000 which equals 4694132100000000

= 5062471257622800
