Trelew, Chubut, is in Argentinian area code 02965. In international format, that's +54 2965.
(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, and many other countries use different prefixes.)
The telephone country code for Argentina is +54. The area code for Arrecifes is 02478, or +54 2478 in international format.
The telephone country code for Argentina is +54. The area code for Chascomus is 02241, or +54 2241 in international format.
The telephone country code for Argentina is +54. The area code for Escobar is 03488, or +54 3488 in international format.
The telephone country code for Argentina is +54. The area code for Formosa is 03717, or +54 3717 in international format.
The telephone country code for Argentina is +54. The area code for Bahia Blanca is 0291, or +54 291 in international format.
The telephone country code for Argentina is +54. The area code for Carlos Spegazzini is 02274, or +54 2274 in international format.
The telephone country code for Argentina is +54. The area code for Chascomus is 02241, or +54 2241 in international format.
The telephone country code for Argentina is +54. The area code for Laprida is 02285, or +54 2285 in international format.
The telephone country code for Argentina is +54. The area code for Clorinda is 03718, or +54 3718 in international format.
The telephone country code for Argentina is +54. The area code for Acebal is 03469, or +54 3469 in international format.
The telephone country code for Argentina is +54. The area code for Aimogasta is 03827, or +54 3827 in international format.
The telephone country code for Argentina is +54. The area code for Alcaraz is 03438, or +54 3438 in international format.
The telephone country code for Argentina is +54. The area code for Andalgala is 03835, or +54 3835 in international format.
The telephone country code for Argentina is +54. The area code for Apostoles is 03758, or +54 3758 in international format.
The telephone country code for Argentina is +54. The area code for Ayacucho is 02296, or +54 2296 in international format.
The telephone country code for Argentina is +54. The area code for Azul is 02281, or +54 2281 in international format.
The telephone country code for Argentina is +54. The area code for Bolivar is 02314, or +54 2314 in international format.
The telephone country code for Argentina is +54. The area code for Bragado is 02342, or +54 2342 in international format.