The California telephone area code 661 covers the majority of Kern County, as well as part of Los Angeles County, Santa Barbara County, and Tulare County. ZIP Codes in the United States have a base of 5 digits, with a four-digit extension, and are used for postal addresses ("snail mail").
Bakersfield, California, is in area code 661.
There is no such thing as "the ZIP code" (singular) for an area code, since area codes are considerably larger than ZIP codes. You will need to look up the ZIP code for a specific address in that area code.
To dial a number in area code 661 from a landline in area code 408, you should dial 1-661 and then the 7-digit local number. On most cellphones, you can dial just 661 and then the 7-digit local number. Maybe your friend moved or just has a different # now.
The area code 479 is for the state of Arkansas. A zip code is for a city or part of a city. By area code alone you cannot determine a zip code.
Area code 661 covers many cities in California, USA, including Bakersfield and Santa Clarita.
ZIP Code 23401 is Keller, Virginia, which is in telephone area code 757.
Area code 661 covers a chunk of southern California, including Bakersfield and northern Los Angeles County (Lancaster, Palmdale, etc.). It covers many different ZIP Codes.
The area code (832) is for the state of Texas. Within that area code there are 44 cities. You cannot determine a zip code by area code.
The country code and area code of Lorestan, Iran is 98, (0)661.
The country code and area code of Bredbyn, Sweden is 46, (0)661.
The country code and area code of Madaripur, Bangladesh is 880, (0)661.
The country code and area code of Fulda, Germany is 49, (0)661.