What is N (subscript) 0?

Hi there, does anyone know how to interpret this figure and its corresponding translation to Spanish?

n₀: 2200/min

Looks like a frequency....Do you any context?

That is part of a machine label specifying its feature:

Attachment 555

Maybe you can find something useful in this link
https://en.wikipedia.org/wiki/Eb/N0

Mmm, not sure if it has to do with noise power.

That is a frequency: https://en.wikipedia.org/wiki/Frequency
A frequency of what? It all depends on the context.

I see. That is possible.
Thank you there :)