Estonia uses country code +372(dialed as 00 372 from many places).
(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.)
Country code +372 is Estonia, and +372 81 is a mobile.
The country code and area code of Dushanbe, Tajikistan is 992, (8)372.
The country code and area code of Ljungby, Sweden is 46, (0)372.
The country code and area code of Zonguldak, Turkey is 90, (0)372.
The country code and area code of Amacueca, Mexico is 52, (01)372.
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.