573-884 is the prefix for the University of Missouri but the number is not listed in its internal directory. It is probably a telemarketer masking their real number with a more credible MU telephone number
I got the call but didn't answer the phone because I didn't know the number. I thought that they would leave a voicemail but they didn't so it couldn't have been anything that important if no message was left.
I've been getting calls from this number, 882-8952 and 884-2576 on my cell phone here in Northern California. Leave no messages. All come up as U of MO. Fishy business if you ask me, as my cell is on the no call list.