Computers take input, process (compute) and produce output. The brain in many ways is the same except it is self-aware, capable of original thought, self-destruction, output without reason or input, processing information arbitrarily without any input or prompt and most importantly: question itself and the world around it and develop new programs to evaluate and process previously unseen input to generate desired output.

You can continue to keep calling it a computer but that is like calling an ICBM a projectile or the planet earth a big rock with water on it. Technically correct but those aren't the best or most specific and descriptive way of refering to these things.

Perhaps the better question is: Is the computer a brain? Not yet!

A human brain cannot sensibly operate without inputs, look up “sensory deprivation effects”. But that’s just a nitpick.

I don’t think we should even compare silicone and biological computing. At the hardware level, there is no way a computer could become a brain by some sort of organic transition. But also I think that the hierarchy your question is implying is not correct. Theoretical “computer brains” do not have to resemble biological ones neither in construction nor in function. I believe when we will create (or meet) electronics-based intelligence with enough properties from your list, there will still be a period of a rejection, because humans tend to exalt their own way of existence and operation above others.