Alright, let's work through 51499613 times 13333390 step by step
51499613 × 13333390 = 13333390 × (51499613)
+ 13333390 × 3 resulting in 40000170
+ 13333390 × 10 that results in 133333900
+ 13333390 × 600 resulting in 8000034000
+ 13333390 × 9000 that results in 120000510000
+ 13333390 × 90000 which equals 1200005100000
+ 13333390 × 400000 what gives us 5333356000000
+ 13333390 × 1000000 which equals 13333390000000
+ 13333390 × 50000000 which equals 666669500000000

= 686664424978070
