It seems that every Pagan religion I've heard of is Polytheistic or Pantheistic.
And isn't Islam basically just Paganism in monotheistic wrapping paper? I mean it is different from the Christian and Jewish religion.
Some Pagans are in fact monotheistic. Some Pagans will say, like some Hindus, that the many deities are different aspects or faces of one ultimate higher reality, creator, whatever. The Church and School of Wicca considers itself monotheistic. Of course, it doesn't consider itself Pagan.
I'd say most Pagans are duotheistic (most Wiccans/Witches), pantheistic, or polytheistic. Some are even agnostic.
Is Islam Pagan?? Oh, mercy! Let's see. Idols strictly prohibited. The worship of other deities strictly forbidden (unlike many Pagan religions, where you can mix and match). Nature worship prohibited. And I'd imagine that magic, witchcraft and the occult are also forbidden. Islam is hardly different than it's 2 older predecessors. One god, the supposedly only true faith, women have often been maltreated, unhealthy obsession with taboos over sexuality... No, Islam is definitely not Pagan...
Regarding Christianity, it is basically a mixture of Judaism, Zoroastrianism, and Paganism. Catholic and Orthodox churches are steeped in Paganism, of course won't admit it. Pentecostalism, with the speaking in tongues thing and the emphasis on healing and visions, totally Pagan/occult. Funny how people tend to be highly influenced by the things they condemn so loudly.