It's ~650GiB of data. The entire English version of Wikipedia is about 20GiB and the Encyclopædia Britannica is only about 300MiB (measured in ASCII characters) [1].
I only use the sources available to me at the time.
Another value published by Wikipedia is 30GiB [1] as of 2020, which includes punctuation and markup.
I explicitly put the measurement unit as ASCII characters. If you have a better source for your size (remember: ASCII characters for article words only, no markup), feel free to post it.
It's ~650GiB of data. The entire English version of Wikipedia is about 20GiB and the Encyclopædia Britannica is only about 300MiB (measured in ASCII characters) [1].
[1] https://en.wikipedia.org/wiki/Wikipedia:Size_comparisons