Let’s call x the number of your expression. Work with logarithms (for convenience, with decimal logs):
Log(x)=(5.53*10^9861)*Log[] .... an so on ....
Log(x)= (5.53*10^9861) * (1.15*10^9866) * (8.65*10^9862) * Log(1.42*10^9864)
Log(x) = (5.53 * 1.15 * 8.65) * 10^29589 * (Log(1.42) + 9864)
Log(x) = 5.42… * 10^29594
Thus, x is a really huge number. (Yet Log(x) is really huge!)
By comparison: Nowadays, the total number of particles in the universe has been variously estimated at numbers from 10^72 up to 10^87.
Where does this question come from?
Regards
Z