The CPU can be 64 bit capable but the software running on it 32 bit. This is very common for vendors to do and which is why it won't install.
If your device does not meet the requirements, it will fail to install. Unfortunately android doesn't give us a good way of telling the user that without a lot of work on our end.
If your device does not meet the requirements, it will fail to install. Unfortunately android doesn't give us a good way of telling the user that without a lot of work on our end.