+770 is not a valid international calling code. However, +1 770 is a valid area code in North America, serving suburbs of Atlanta, GA, USA.
Telephone country code +7 is Russia and Kazakhstan. A number beginning with +7 70 is a mobile in Kazakhstan.
(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.
where is telephone country code 1816
That is not a country code.
The country code and area code of Fangchenggang- GX, China is 86, (0)770.
Fiji has telephone country code +679.
Country code +57 is Colombia.
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.