Why is the APK filesize and Installed size is so huge?

I made a veeery simple game with little over 3mb of textures compressed. I checked the editor log and found out that the included dll are at least 4mb. So over all it was 7mb but it ended up being 10mb so I decided to just let it happen for now.

I installed the game on my phone and noticed that the installed size is over 47mb…

Anyone have any ideas why?

Apologies if the question is vague.

I really need help as soon as possible. Now that I implemented google play game services, the apk is now 12mb but when I install it on my phone, it’s over 100mb. What the heck lol…