How do you pronounce pietrisycamollaviadelrechiotemexity?

That's a very long and unusual word! It's likely a made-up word, as there isn't a word like that in any major language.

If you want to pronounce it, you could break it down into syllables and try to guess the sounds:

Pie-tri-sy-cam-ol-la-vi-a-del-re-chi-o-te-mex-i-ty

But without knowing the origin or meaning of the word, it's difficult to give a definitive pronunciation.