How to get latitude /longitude in Degree Minute Second (DMS) using QGIS field calculator?

I have come up with the following expression to convert 5.1234 to 5° 7`24.24"

toint ($x) || '° ' || toint((($x) - toint ($x)) * 60) ||'`' || substr( (tostring(((($x) - toint ($x)) * 60) - toint((($x) - toint ($x)) * 60)) * 60),1,5) || '"'

Here’s the problem : for some points such as 5.1234, it works. but for others, it doesn’t. I suspect the problem is the integer conversion which round up the decimal figures instead of truncating it.

Is there any other option? thanks.