How to understand that an audio file in mpeg-4 format is broken?

Question

iPhone

Recorded yes voice recorder recording in mpeg-4 format. Recordings longer than 20 minutes. Recorded from an apple 6 device > voice recorder.
I tried to open audio through a computer through different audio players > did not work out
Tried to convert to mp3 format > gives an error.
If anyone knows what is wrong with this file, then help me figure it out.
I've been on my phone all day today and can't find a solution. And it is not possible to check whether the file is broken from the phone or not.