Country codes beginning with +3 (dialed as 00 3 from many places) are in Europe, but you need the full two- or three-digit code to be specific.
+30 = Greece
+31 = Netherlands
+32 = Belgium
+33 = France
+34 = Spain
+35 = (see below)
+36 = Hungary
+37 = (see below)
+38 = (see below)
+39 = Italy
+350 = Gibraltar
+351 = Portugal
+352 = Luxembourg
+353 = Republic of Ireland
+354 = Iceland
+355 = Albania
+356 = Malta
+357 = Cyprus
+358 = Finland
+359 = Bulgaria
+370 = Lithuania
+371 = Latvia
+372 = Estonia
+373 = Moldova
+374 = Armenia
+375 = Belarus
+376 = Andorra
+377 = Monaco
+378 = San Marino
+379 = Vatican City (assigned but not yet in service; use +39 06 698)
+380 = Ukraine
+381 = Serbia
+382 = Montenegro
+385 = Croatia
+386 = Slovenia
+387 = Bosnia and Herzegovina
+388 = (was pan-European numbers, now unused)
+389 = Republic of Macedonia
(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.)
Leichtenstein is telephone country code +423.
Telephone country code +221 is Senegal, in western Africa, but there are no valid telephone numbers beginning with +221 4.
where is telephone country code 1816
That is not a country code.
The telephone country code for France is +33. The area code for the southeastern quadrant of the country, including the island of Corsica, is 04, or +33 4 in international format.
The telephone country code for France is +33. The area code for Corsica is 04, or +33 4 in international format. The local number is a further 8 digits.
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.