Alright, let's work through 12523747 times 52031907 step by step
12523747 × 52031907 = 52031907 × (12523747)
+ 52031907 × 7 producing 364223349
+ 52031907 × 40 that results in 2081276280
+ 52031907 × 700 which equals 36422334900
+ 52031907 × 3000 what gives us 156095721000
+ 52031907 × 20000 producing 1040638140000
+ 52031907 × 500000 which equals 26015953500000
+ 52031907 × 2000000 giving us 104063814000000
+ 52031907 × 10000000 yielding 520319070000000

= 651634439195529
