Depending on how you count, the human brain is between 100 trillion and 1 quadrillion parameters, which is one guess as to why we're so much more sample efficient at learning than LLMs are.
LLMs need an awful lot of handholding all the time, meanwhile humans get pretty good at it on their own.
I mean we literally do this every few seconds already with natural birth processes.
Trying to estimate equivalent "parameter size" of the brain when we only superficially understand behavior of individual neurons let alone how intelligence emerges from the connectome seems too speculative to be a particularly useful metric.