Alright, let's work through 77347515 times 51491351 step by step
77347515 × 51491351 = 51491351 × (77347515)
+ 51491351 × 5 giving us 257456755
+ 51491351 × 10 producing 514913510
+ 51491351 × 500 producing 25745675500
+ 51491351 × 7000 yielding 360439457000
+ 51491351 × 40000 giving us 2059654040000
+ 51491351 × 300000 resulting in 15447405300000
+ 51491351 × 7000000 yielding 360439457000000
+ 51491351 × 70000000 what gives us 3604394570000000

= 3982728043842765
