Search for it in C:\Program Files or C:\Program Files (x86) folder. In my case it is located here:
C:\Program Files (x86)\Microsoft Office\Updates\Download\PackageFiles\112CBB07-F673-4D5C-8BD6-16CD94728257\root\Office16
You will also be able to open iy via Start Menu > All programs.
Outlook.exe is located in a subfolder of "C:\Program Files (x86)"—usually C:\Program Files (x86)\Microsoft Office\Office14\. Known file sizes on Windows 10/8/7/XP are 13,179,660 bytes (84% of all occurrences), 196,440 bytes and 7 more variants.