The product of the number and 500 will be 2100000.
Explanation
Suppose, the number is [tex]x[/tex]
The number is 42,000 when multiplied by 10. So, the equation will be......
[tex]x*10= 42000\\ \\ x=\frac{42000}{10}=4200[/tex]
So, the number will be 4200
Now, the product of this number and 500 will be: [tex]4200*500= 2100000[/tex]