In some cases, multi-part archives are labeled numerically (e.g., AN.part1.rar, AN.part2.rar). However, the "(3)" format is more characteristic of a duplicate download.
Use an online scanner like VirusTotal to check the file against multiple security databases before extracting. AN (3).rar
Most web browsers automatically add "(1)", "(2)", or "(3)" to a filename if you download the same file multiple times to the same directory. In some cases, multi-part archives are labeled numerically