Cameras have a min and max ISO, not a "native" ISO.

Yes they do have a native ISO. It's generally whichever ISO produces the greatest dynamic range.

Camera sensors have a base sensitivity that will capture an image without additional voltage applied to it. Adding voltage allows the sensor to capture more information, at the cost of additional noise. The lower ISO values are also not usually the native, instead they are simulated in camera. The camera algorithms are pretty good these days, but they can still end up with clipping sensor data that you might want.

The native ISO isn't usually published along with typical product specs, but you can usually find it by searching online.

That's not entirely accurate. The native ISO ("base sensitivity") just means no analog gain is applied. This is a fairly complex area, but to simplify - for non-dual gain sensors - the sensor captures the same amount of information regardless of ISO setting. The ISO setting then determines how much analog gain to apply, and also how much digital multiplication to apply (if the ISO setting is outside of the analog gain range). No additional information is captured at higher ISO values.