Do not answer this number, or any other number you do not recognize. Just picking up the phone can put you at risk for scams. Scammers will note that your number is "live" and either sell the list to another scammer, or try to use social engineering to get you to give up your personal information. The NPR article that sfritz referenced in the comments is a good reference to learn how these people operate. If someone legit wants to talk to you, you will either a) already have their number saved and know who it is, or b) they will leave a message. Please share this information with seniors and other vulnerable parties who might fall victim to these scams.
WARNING--BEWARE!! These callers are B I G credit card criminals, known as the card service scammers! Under NO circumstances, give these lowlifes your credit card number, or you will regret it forever!
They called at 6:08 am on a Saturday. Gave me the option of press 1to be put on the DNC or 2 for a live operator. I pressed 2, and said it was 6 in the morning. Hung up on me when I told them the time. I called the number later to get the name and only got a recording to press 1 to be put on the DNC.