The fact that you knew the numbers for your friend suggests to me that maybe you like numbers? I can barely remember the year someone died, let alone all that detailed information. So if your conscious mind is good with numbers, then your unconscious mind is also. Your unconscious is probably processing the death of your friend, and the numbers is one way to do it.

I wouldn't take it as any ominous omen that that is the date you'll die or anything like that. I do a lot of dream work with my therapist and I'm finding it absolutely fascinating how the mind works when we're asleep! It is really helping me in therapy to analyze my dreams. In fact, my therapist is so interested in dreams that he says it's like "talking to another person."

I'm sorry about the loss of your friend. It may be bothering you more than you're conscious of.