No, it's not the actual encryption key -- that would be a massive security issue. It's the key's location or alias in the radio's encryption table. Radios may use more than 1 key if they access multiple systems, or if they use multiple keys in the same system, so the system reports which key location is being used for the particular TG active at the moment. 5D75 is hex, and 23925 is the decimal equiv.