Telephone country code 121 does not correspond to any specific country. Country codes are assigned by the International Telecommunication Union (ITU) and typically consist of one, two, or three digits. The United States, for example, has the country code +1, while India has the country code +91. Country code 121 is not allocated to any country and is not in use for international dialing.
Telephone country code +1 is North America (USA, Canada, etc.), but there is no area code 121 in North America. It is an invalid number.
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
Country code +57 is Colombia.
Country code 52 is Mexico.
Fiji has telephone country code +679.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Vanuatu is country code +678.
Niue is country code +683.