Telephone country codes never begin with zero.
Telephone country code +1, dialed as 00 1 from many places, is North America (USA, Canada, etc.), and 4 is the first digit of a three-digit area code. You need the next two digits to narrow down the location.
Telephone country code +4, dialed as 001 4 from many places, is an incomplete code somewhere in Europe. You need the next one or two digits to narrow down the country.
0014 is also used as an international dialing prefix in Australia, specifically for sending faxes on the Telstra network.
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 +44), 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.)
0024 - is incomplete. The next digit after the 4 is needed to specify the country it belongs to. There are TEN countries with IDC beginning 0024 !
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.