Why apk size is way too big??

I’d build a simple android game in unity 5.6 Personal. After a build I went through Console > Open Editor Log and following size information was retrieved. But my apk file size is 20.5MB and when I installed it on android device it takes size of 70 MB. Why the size of my game is so big? What can I do anything to reduce file size??

98901-popop.png

Man, check this out Unity - Manual: Reducing the file size of your build

You can build your apk for individual platform architectures.

Go to Build Settings (or press Ctrl+Shift+B) → Click on Player Settings → Select Android and click Other Settings → Check the option Split APK by target architecture

129689-2.png