What is up with these strange and long coordinate strings and is there a way I can convert them?

I have some geoJSON where each polygon looks similar to this:

   {
   "geometry":{
      "type":"Polygon",
      "coordinates":[
         [
            [
               "0045100491005010050100461005110050100511005010049100531004810048",
               "005210057100461004810052100491005510048100521004810048"
            ],
            [
               "0045100491005010050100461005110050100511005010050100561004810048",
               "005210057100461004810052100491005610050100501004810048"
            ],
            ...
         ]
      ]
   }
}

I'm struggling to make heads or tails of these coordinates or how to get them into a usable state.