This number was somehow put into my phone as a most dialed number. I never leave my phone unattended.

This phone sent voice message to me but nothing in the message,

This number was somehow put into my phone too as a most dialed number. I never leave my phone unattended also.

I believe this number is for those persons using or that have voice mail for the phone service from Seven Eleven-SpeakOUT.

This is why you may see it a number of times on your phone but don't remember actually calling it. Also could be why a person would put it as a contact/favorite number to have it handy or note what it is in reference to. It will also appear as a number dialed if you use the quick access feature of hold "1" down on your phone to "call/access" your voice messages while you are with this service.

Yup, It;s the Eleven-SpeakOUT service.