Alright, let's work through 78973624 times 77959961 step by step
78973624 × 77959961 = 77959961 × (78973624)
+ 77959961 × 4 which equals 311839844
+ 77959961 × 20 what gives us 1559199220
+ 77959961 × 600 that results in 46775976600
+ 77959961 × 3000 that results in 233879883000
+ 77959961 × 70000 that equals 5457197270000
+ 77959961 × 900000 which equals 70163964900000
+ 77959961 × 8000000 producing 623679688000000
+ 77959961 × 70000000 yielding 5457197270000000

= 6156780647068664
