Telephone country codes never begin with zero.
Country code +1, dialed as 00 1 from many places, is North America (USA, Canada, etc.). You need the three-digit area code (i.e., one more digit) to narrow down the location.
Country code +64, dialed as 001 64 from many places, is New Zealand.
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., +1 or +64), 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.)
The country code 00164 corresponds to the United States Virgin Islands. This territory is located in the Caribbean and is an unincorporated territory of the United States. The US Virgin Islands consist of several islands, including St. Thomas, St. John, and St. Croix.
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.