Although it is, as you say, "generally thought that all life descended from one original single-celled [organism]," the issue doesn't seem settled among the experts, as reported here.
But regardless of the resolution of that issue, I'd answer no to your question. Each of the numbers you mentioned is unique. Any card in an ordinary deck is as unlikely to be drawn as any other; it's just that we arbitrarily assign special significance to particular cards, such as the ace of spades. Similarly, we may assign special significance to the number 1 or (simply because we use a base-10 system) the number 1 million, despite the fact that every number is unique. Furthermore, it's not clearly true that "all the life which exists in all the known universe seems to have arisen from one ancestor." More accurately, it's "all the life we know of seems to have arisen from one ancestor." The life we know of may constitute a small sample of all the life that exists, as yet unknown to us, in the known universe: almost all of the known universe isn't well known by us!