Pillar and Cluster Content

I was wondering about the optimal word count for clusters and pillar posts. I read somewhere that pillar word count is much higher than cluster. Do you guys know what is the minimum and the maximum number of words for the pillar content?

Generally main content (Pillar) consist of 2k+ to 3k+ words and branches (cluster) consist of 700 to 1000 words. But it differ from niche to niche.