+674

Country Code: +674
International Call Prefix: 00

National Significant Numbers (NSN): seven-digits

Format: +674 yyy xxxx

5596085

August 2011: Criden Appi, Director of Telecommunications (Regulatory), Nauru advises "only 556xxxx, 557xxxx, 558xxxx are in use for mobiles and there are no landlines in service".

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Wikipedia