Alright, let's work through 77641678 times 28509315 step by step
77641678 × 28509315 = 28509315 × (77641678)
+ 28509315 × 8 that equals 228074520
+ 28509315 × 70 yielding 1995652050
+ 28509315 × 600 which equals 17105589000
+ 28509315 × 1000 resulting in 28509315000
+ 28509315 × 40000 producing 1140372600000
+ 28509315 × 600000 producing 17105589000000
+ 28509315 × 7000000 yielding 199565205000000
+ 28509315 × 70000000 producing 1995652050000000

= 2213511055230570
