How to round a big number to significant figures, without expressing it using e? in jquery

Question

I'm trying to round the value pulled from an API, without expressing it using e.

At the moment I'm getting the value 6.65e+7. I want the value to be 66,500,000.

Here's the code I'm using at the moment:

   function precise(x) {
   return Number.parseFloat(x).toPrecision(3);
   }
                  
   $('#population').html(precise(result['data']['geonames'][0]['population']).toString());