I also noticed the math error later, but thank you for pointing it out. Also... "non-anthropocentric" is the word I was looking for earlier. Thank you!
I also ended up looking at the milkyway star count, and it's viable, but also a bit broad, having a range of 100 to 400 billion, which I could write around (having that number embeded in the signal too) but I'd still prefer something less vague if it can be worked out.
Right now, I've got this: Pi X Efficency of Hydrogen Fusion (.007) X Golden Ratio X larger end of the current Galactic Count (~348,000,000,000) = about 13 years as meassured in Crab Pulsar rotations. (Wolfram Alpha Link).
I also read something about the pulsar's having a slight slowing, but I thought it was so minor that it's wouldn't really matter. It'll slow down by about .15 seconds in 13 years if I did the math right, which won't effect my story concept at all... although you do note it might make a fun detail. Classic scientist trope of being overly spicific on the time range "give or take .15 seconds depending on if they acounted for spin down or not."
Thank you for the help so far. I'd still really love to find a non-anthropocentric replacement for the number of stars in the galaxy. I'd still be fine with a handful of other numbers in it's place. I'm realizing that ratios work well, as do atomic counts.
I've been considering for vaibility:
Atomic number of lead 82 (the largest atomic number for a stable element.)
145,000, the ratio of the size of a hydrogen atom to the size of it's nucleus
The temperature of the cosmic background radiation in Planck Temperature (3.861×10^32) (I think planck temperature is non-anthropocentric, and that the cosmic background radiation temperature falls in a small enough band that it coud work as a number) It's sadly too large a number.