I live in Denver city , Arapahoe county.
Since Denver county and city are synonymous, if you're in Arapahoe county, you're not in either Denver city or Denver county.
Here are the zip codes for the county of Denver, Colorado. Most are 100%, that is, if you're in that zip code, you're in Denver. A few cross county lines, so if you're that zip code, you may be in another county.
80201
80202
80203
80204
80205
80206
80207
80208
80209
80210
80211
80212
80216
80217
80218
80219
80220
80222
80223
80224
80230
80231
80236
80237
80238
80239
80243
80244
80246
80248
80249
80250
80251
80252
80256
80257
80259
80261
80262
80263
80264
80265
80266
80271
80273
80274
80279
80280
80281
80290
80291
80293
80294
80295
80299 .