Alright, let's work through 78346595 times 64873821 step by step
78346595 × 64873821 = 64873821 × (78346595)
+ 64873821 × 5 what gives us 324369105
+ 64873821 × 90 what gives us 5838643890
+ 64873821 × 500 giving us 32436910500
+ 64873821 × 6000 resulting in 389242926000
+ 64873821 × 40000 giving us 2594952840000
+ 64873821 × 300000 what gives us 19462146300000
+ 64873821 × 8000000 that equals 518990568000000
+ 64873821 × 70000000 that equals 4541167470000000

= 5082642979989495
