Anguilla is part of the North American Numbering Plan, telephone country code +1, along with the USA, Canada, and various other islands. Anguilla uses area code +1 264, chosen because 264=ANG on the telephone dial.
Calls from the US and other NANP locations to Anguilla are dialed "one plus," the same as domestic long-distance calls, but international rates will apply.
(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 Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
There is no 909 country code.
Anguilla is an English-speaking country.
There is no telephone country code +897, nor +89, nor any other country code beginning with +89. There are no valid telephone numbers beginning with +89.
Gibraltar is country code +350.
Moldova is country code +373.
Slovenia is country code +386.
Togo is country code +228.
Liberia is country code +231.
Angola is country code +244.