Alright, let's work through 10394497 times 64813406 step by step
10394497 × 64813406 = 64813406 × (10394497)
+ 64813406 × 7 giving us 453693842
+ 64813406 × 90 resulting in 5833206540
+ 64813406 × 400 that results in 25925362400
+ 64813406 × 4000 what gives us 259253624000
+ 64813406 × 90000 that is equal 5833206540000
+ 64813406 × 300000 that results in 19444021800000
+ 64813406 × 0000000 giving us 0
+ 64813406 × 10000000 that equals 648134060000000

= 673702754226782
