Here is how Cafayate phone numbers are configured: (3868) 44 4444
Here is how Salta phone numbers are configured: (387) 555 5555
Area code + cell number always total 10 digits.
Many times you will see phone numbers given with an extra 15. (For example: 387 15 555 5555) You can dial it this way, it doesn’t hurt. You have to dial the 15 only if calling a cell phone from a landline.
You will also often see a 0 on the front (03868 44 4444). That is optional as well.
Calling Salta to Salta (or Cafayate to Cafayate) you can drop the local prefix and just dial the phone number. (ie. 555 5555, or 44 4444).
Numbers in Buenos Aires will start with 11, Mendoza with 261, Cordoba with 351, …
To call a mobile in Argentina from abroad, you need to add the country code 54 and 9. So to call a cell phone in Salta from abroad, you dial: +54 9 (387 555 5555). Please make sure to drop the extra 15, just in case.
Please read the above three days in a row and the simple logic might reveal itself.
The excellent www.projectargentinablog.com also have a good article on how to get set up with a cellphone in Argentina.