In order to find the number times something is larger than something, you have to use division where you divide the larger number by the smaller number.
So: 3.19x10^8= 387.6063183
8.23x10^5
I'm not sure how much you want to round to, but the answer is 387.6063183 times.
You can make sure by multiplying the smaller number by 387.6063183 and you should get the larger number:
8.25 x 10^5 x 387.6063183= 3.19 x 10^8
I hope I'm not wrong