I tried looking the number up but didn't have much luck. They called me about 2-3 times a day the past 4 days so I finally had enough and blocked them.
It is a robocall. Calls me twice a day, around 12:15 p.m. and around 3 p.m. every day. This has been going on since early October. Recording says that I must call another number to talk to a customer service representative about my Citi account (which I don't have). Recording says it is very important that I call that other number.