Mobile is a broad notion.... and I think you actually mean Windows, as Microsoft is making a killing on Android and iOS through Office 365, OneDrive and OneDrive for Business, Azure Cloud Services which iCloud is built on top of.... also their Patient Payments from Android is a Billion Dollar Business and Apple pays a bunch of fees on every iOS device....
Now when we talk about Windows, there are 23 Billion Windows Devices with the majority of those are mobile platforms.... as far as Applications overall Windows leads there too....