Alright, let's work through 16891307 times 38971878 step by step
16891307 × 38971878 = 38971878 × (16891307)
+ 38971878 × 7 giving us 272803146
+ 38971878 × 00 that is equal 0
+ 38971878 × 300 giving us 11691563400
+ 38971878 × 1000 that equals 38971878000
+ 38971878 × 90000 which equals 3507469020000
+ 38971878 × 800000 that equals 31177502400000
+ 38971878 × 6000000 which equals 233831268000000
+ 38971878 × 10000000 which equals 389718780000000

= 658285955664546
