There is no area code 678 in Mexico.
678 is an Atlanta, GA area code
The area code for Marietta, GA is 770, with overlay codes 678 and 470.
Winder, GA, is in area codes 770, 678, and 470 (multi-overlay).
The country code and area code of Santa Rosa Del Monday, Paraguay is 595, (0)678.
505 is the area code for Zuni, New Mexico.
The country code and area code of Abasolo, Mexico is 52, (01)429.
The country code and area code of Acacoyagua, Mexico is 52, (01)918.
The country code and area code of Acambaro, Mexico is 52, (01)417.
The country code and area code of Acambay, Mexico is 52, (01)718.
The country code and area code of Acamixtla, Mexico is 52, (01)762.
The country code and area code of Acanceh, Mexico is 52, (01)988.
The country code and area code of Acapetlahuaya, Mexico is 52, (01)736.