Is there any way to get rid of the missed call notification without calling the number back

Swipe left ue=r right on the call in the Recent list and press the Delete button.

I will add that you CAN get rid of the number icon with Malcolm's description - swiping L to R at the right side of the call as listed in the Recent Calls list. You don't have to delete the call as he suggests, though.

This is a pain though. I will share on Apple's feedback that they should have those icons disappear when the message has been seen, as in on the notification screen or some place more convenient that having to go all the way into Phone>Recents>swipe.

Open the phone app and tap on recent that should remove the notification. Also in the pull down notification centre tap on the X to the right of the missed call and that will clear it.

Or you can just tap on the little blue chevron on the right side of the notification entry in the list. It takes you to the details. Still more than one step.

Clearing it in Notifications does not clear the number icon on the corner of the phone app icon.