Alright, let's work through 66345841 times 78758913 step by step
66345841 × 78758913 = 78758913 × (66345841)
+ 78758913 × 1 which equals 78758913
+ 78758913 × 40 what gives us 3150356520
+ 78758913 × 800 that is equal 63007130400
+ 78758913 × 5000 yielding 393794565000
+ 78758913 × 40000 resulting in 3150356520000
+ 78758913 × 300000 producing 23627673900000
+ 78758913 × 6000000 giving us 472553478000000
+ 78758913 × 60000000 that equals 4725534780000000

= 5225326319230833
