According to Mohammed, his prophet, it is. Can you disprove his contention?
There are 1.5 billion people in the world that agree with him and would shove it down your neck if they had the chance.
Yeah and there were umpteen billion chinese waving a little red book with the same intent. That doesn't make it the word of God. BTW, the Koran was supposedly revealed to one man over his lifetime. The Bible was revealed to many men over millenia.
Can I prove that the Koran is no word of God?
I would say that we know specifically when it came on the scene, who wrote it, and what his life and his death was like.
Showing that allah is not the God of Christians and Jews is fairly simple. Showing the murderous side of mohammed and his movement is fairly simple.