Country codes beginning +87 are global services, not specific to any country.
+870 = Inmarsat, mostly for ship-to-shore calling
+878 = universal personal numbers
+871 through +874 were formerly used for Inmarsat
+875, +876, and +877 are reserved for maritime satellite phone services
+879 is reserved for an unspecified non-commercial service
There is no telephone country code +87 (or 00 87).
Inmarsat satellite phones use country code +870.
Inmarsat formerly also used country codes +871, +872, +873, and +874.
Country codes +875, +876, and +877 are for maritime mobile telephony.
Country code +878 is for Universal Personal Numbers.
Country code +879 is reserved for unspecified future "non-commercial purposes."
(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.)
Telephone country code +877 (which would be dialed as 00 877 from many places) is assigned for future maritime mobile uses, but it is not yet in use. As of January 2014, there are no valid telephone numbers in country code +877.
In North America (USA, Canada, etc.), area code 877 is a domestic toll-free number. It may be possible to dial it from outside North America as +1 877, although international toll charges will most likely 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 North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)
Telephone country codes never begin with zero.
Country code +87, dialed as 00 87 from many places, is an incomplete code for a transnational telephone service. You need at least one more digit to identify the service. For example, +870 is Inmarsat satellite phones and +878 is Universal Personal Numbers.
Country code +7, dialed as 008 7 from many places, is Russia and Kazakhstan.
To avoid confusion, it is best to write an international telephone number in correct international format, beginning with the plus symbol and the correct telephone country code (e.g., +870 or +7), omitting any dialing prefix.
(The plus signmeans "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.
There is no 909 country code.
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.
Mozambique is country code +258.