Security of data is critical given the rapid development of information technology due to the illegal access to personal or confidential data. This has made security methods to hide secret messages urgent to implement, one of which is hiding a secret message (payload) into a medium (cover), like an audio file. However, this general technique has some drawbacks, mainly are the small space to hold the data and the large difference between the stego-audio and the original audio. In addition, there is a risk of irreversible payload upon extraction. To solve this problem, we propose using the Least Prime Factor of the difference between the interpolated data and the original audio to find the sample space, partition the payload using the specified sample space, and embed the decimal payload into the interpolated sample. The result shows that the method can work well on those payload capacity and stego-audio quality issues.