Telephone country code +1 is North America, including the USA and Canada plus some miscellaneous island countries and territories.
Telephone area code +1 818 serves the San Fernando Valley area of greater Los Angeles, California, USA. Area code +1 747 is an overlay on +1 818, serving the same communities. Several other area codes serve other parts of the Los Angeles metropolitan area.
(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.
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.
Togo is country code +228.