Is 5 random?
Depends. By definition, randomness is a property of process which follows the uniform distribution. So if an "event" occurs over time such that each outcome is equally likely, then we say it is random.
It doesn't mean there is this unknowable mystery...it's simply unknowable to us because it is impossible to make exact measurements of everything involved.
Same reason why the weather is not random 1 hour from now...but it is random 356 days from now.
Or the stock market might be predictable in terms of movements an hour from now, but not 4567 hours from now.