Alright, let's work through 64070635 times 78745423 step by step
64070635 × 78745423 = 78745423 × (64070635)
+ 78745423 × 5 that results in 393727115
+ 78745423 × 30 that is equal 2362362690
+ 78745423 × 600 that equals 47247253800
+ 78745423 × 0000 that results in 0
+ 78745423 × 70000 resulting in 5512179610000
+ 78745423 × 000000 what gives us 0
+ 78745423 × 4000000 resulting in 314981692000000
+ 78745423 × 60000000 that is equal 4724725380000000

= 5045269254953605
