Well, there seem to be two problems. First, I overlooked the fact that the number coming out of textfile has to be converted to a symbol before going into [symbol2list]. [list2symbol] actually does that, so sticking it inbetween [textfile] and [symbol2list] works.
However, more importantly is the problem of your text file. The number in it is just too large for Pd to handle; it has to fall within the range of 32-bit floating point numbers. It's instead spitting out "1.#INF", which I'm guessing is supposed to mean infinity. But even if it does fall within the range, Pd has a nasty habit of converting numbers over five digits into scientific notation, which I don't know how to get around. So, if it's possible (or if someone out there has a better solution), I think you might just be better off fixing how you generate the number in the text file to begin with. If you could get each digit on its own line in the text file, Pd will have an easier time.