Install problem on Galaxy S5 Neo

[SilverBeam]

Hi everyone. I know this probably will sound like the n-th identical question but: i can't install dolphin on my S5 Neo. I have read the FAQ, but i can't find the problem: i have an Exynos SoC 64-bit able with a Mali720 cpu ES3 capable. The problem may lie in the OS build: i am currently running a 5.1.1 build, BUT, after countless different tries, i can't figure out a way to discern wether i am on a 32 or 64 bit OS build. Does anyone know a way to check this on an unrooted device?