Now a days much like personal computers and laptops, Android devices are also either 32-bit or 64-bit. This architecture is determined by the hardware specifically the CPU used on the device and there is no changing it. If you want to check if the Android device you have in your hands is 64-bit or 32-bit, You can use one of the following methods to check it.
1. Check Android kernel version
Go to Settings > System and check Kernel version field, if the text written opposite it contains x64 string, your device has a 64-bit OS and if you cannot find this string, then is 32-bit.
2. Using an app
If you find it hard to search through your device’s setting, or the information isn’t there, You can download and install following free apps from the Google Play Store.
Once installed open the app, and then tap on the System tab. Look for the Kernel architecture field and it will tell you if your device is 32-bit or 64-bit.