The airport code for Marshall Islands International Airport is MAJ.
The Aland Islands are part of Finland, which is telephone country code +358.
+692
The Falkland Islands (also known as the Islas Malvinas) are country code +500.
(see related question)
The Solomon Islands use country code +677. There are no city codes or area codes. The local number is 5 or 7 digits.
Telephone country code +1 is North America, including the USA, Canada, and 18 islands in or near the Caribbean, but there is no area code +1 467. There are no valid telephone numbers beginning with +1 467.
The telephone country code for the US (including territories in the Caribbean and Pacific), plus Canada and a bunch of Caribbean/nearby islands, is +1.
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
Telephone country code +1 is North America, including the USA, Canada, and certain Caribbean/nearby islands. Telephone area code +1 937 is for southwestern Ohio, including Dayton but not including Cincinnati.
ISO country code MF is the French northern half of the Caribbean island of Saint-Martin. French Saint-Martin shares telephone country code +590 with Guadeloupe and several other French Caribbean islands. ISO country code SX is the Dutch southern half, Sint Maarten, which is now in North American telephone area code +1 721.