+25 (dialed as 00 25 from many places) is an incomplete code: you need one more digit. Country codes beginning with +25 are generally in East Africa.
+250 - Rwanda
+251 - Ethiopia
+252 - Somalia
+253 - Djibouti
+254 - Kenya
+255 - Tanzania
+256 - Uganda
+257 - Burundi
+258 - Mozambique
+259 - (unused)
(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 +93 is Afghanistan, and area code +93 25 (Afghan domestic telephone area code 025) is the city of Logar, south of Kabul.
The telephone country code for Vietnam is +84. The area code for Lang Son is 025, or +84 25 in international format.
Leichtenstein is telephone country code +423.
where is telephone country code 1816
That is not a country code.
026 appears to be a telephone area code, written in domestic format. It is impossible to know where it is without knowing what country you're asking about.
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.