We have been receiving calls from this number 3 or 4 times a day but it is a hang up every time.
I checked on here and it looks like others are having the same issue. I dialed the number to see who was calling.
It is the Special Olympics Donor Center.
They have an auto dialer that will dial multiple numbers at once, first person to pick up has a person to talk to and everyone else has dead air. Also the Do Not Call list does not apply if you have donated to them. They have 540 days (18 months) by law that they are allowed to contact you until they must remove you from their list.