Telephone country codes never begin with zero.
Country code +55, dialed as 00 55 from many places, is Brazil.
Country code +54, dialed as 005 54 from many places, is Argentina.
To avoid confusion, it is best to write an international telephone number in correct international format, beginning with the plus symbol and the correct telephone country code (e.g., +54 or +55), omitting any dialing prefix.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
Country code +57 is Colombia.
Not a valid code. Telephone country codes never begin with zero, and 0000 is not a valid international access prefix anywhere in the world.
Country code +225 (dialed as 00225 from many places) is Cote d'Ivoire (Ivory Coast), but there are no numbers beginning with +225 00, although there are some numbers that begin with +225 0.
California is not a country.The telephone country code for the United States (plus Canada and several nearby islands, mostly in the Caribbean) is +1.The Internet country code for the United States is .us, and the .ca.us subdomain is specifically for California, but most websites in the U.S. use generic global domains like .com and .net.
Telephone country code 307 is not currently assigned to any country. Country calling codes are assigned by the International Telecommunication Union (ITU) to each country or region in the world. The ITU periodically updates and reassigns these codes to accommodate changes in telecommunications infrastructure and geopolitical boundaries. It is possible that code 307 was once assigned to a country or territory that no longer exists or has been reassigned a different code.
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
There is no telephone country code +897, nor +89, nor any other country code beginning with +89. There are no valid telephone numbers beginning with +89.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Togo is country code +228.
Liberia is country code +231.
Angola is country code +244.
Mozambique is country code +258.
Niue is country code +683.