Alright, let's work through 15405047 times 31287687 step by step
15405047 × 31287687 = 31287687 × (15405047)
+ 31287687 × 7 producing 219013809
+ 31287687 × 40 that equals 1251507480
+ 31287687 × 000 that results in 0
+ 31287687 × 5000 yielding 156438435000
+ 31287687 × 00000 what gives us 0
+ 31287687 × 400000 giving us 12515074800000
+ 31287687 × 5000000 resulting in 156438435000000
+ 31287687 × 10000000 what gives us 312876870000000

= 481988288756289
