The relative permeability of the core may indeed be 2000 but, the magnetism also flows through the air from one end of the rod to the other end and, this massively reduces the effective permeability of the whole inductor to a value that is closer to air.
The graph below is taken from a document entitled “Investigation on an Effective Magnetic Permeability of the Rod-Shaped Ferrites” from this source: -
So, with your length to diameter ratio of 15, the graph suggests the effective permeability to be around 50. The other down side to your coil construction is the spacing between consecutive turns; to maximise inductance you would wind them as close to each other turn as you can, even layering to get the turns closer. So, I would estimate that your effective permeability might be as low as 30.
Inductors, in the main, have closed magnetic cores with or without a small air gap. The air gap can be used to stabilise the inductance against temperature variations and also improve the current handling capabilities.
Your inductor construction would be fine for receiving the magnetic field in an EM transmission because it will concentrate the incident magnetism and give a much improved radio signal but, as a pure inductor it will have poor inductance.
Maybe if you could explain what you were trying to design I might be able to offer some suggestions?