Country code +1 (dialed as 00 1 from many places) is North America (USA, Canada, etc.). You need the following three digits (i.e., one more digit) to be more specific. Area codes 510, 512, 513, 515, 516, 517, and 518 are in the USA; area codes 514 and 519 are in Canada.
However, if your international access prefix is '001,' then you're asking about country code +51, which is Peru.
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 +51), 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 many countries use different prefixes. The international access prefix is not part of the country code.)
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
Fiji has telephone country code +679.
Country code +57 is Colombia.
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.
Togo is country code +228.
Liberia is country code +231.