I keep receiving calls from 18663097621 constantly, which bothers me a lot.

This is Bank of America, calling to offer you their extended "services" such as credit monitoring, life insurance, and yes, even long distance.   When you call BoA themselves, they will deny any connection to that number, but if you pick it up the next time they call, you will see that it is in fact, them.

calls everyday. very annoying

I get this call all the time on my USA Skype-in number.  At least Skype displays the caller ID and I know not to bother with it.

they kept calling me every morning at 11am.

This phone number is Bank of America offering extended services.  You may call 1-888-665-9900 and have your information put on the do not call list.  You do not speak with a live person.

This is SOOOOO annoying, i get calls from this number at least3 times a day, and if i pick up there's NO answer!.It's very frusterating!

Yeah, they've been calling me for it seems at least a year and there's never anyone on the other end - and they call me at least 3 Xs a day too.  So, I called that number and it is indeed Bank of America.  If you call the phone number you can list your number on the "do-not-call" list.  Takes about 30 days they say for it to take effect.  I pray it does.  Hope this helps.

They keep calling though I told them to stop calling my number but the demons never stop calling!