Alright, let's work through 51100959 times 78213013 step by step
51100959 × 78213013 = 78213013 × (51100959)
+ 78213013 × 9 producing 703917117
+ 78213013 × 50 that equals 3910650650
+ 78213013 × 900 what gives us 70391711700
+ 78213013 × 0000 what gives us 0
+ 78213013 × 00000 which equals 0
+ 78213013 × 100000 yielding 7821301300000
+ 78213013 × 1000000 that equals 78213013000000
+ 78213013 × 50000000 that is equal 3910650650000000

= 3996759970579467
