Name--hierophant was the title of the chief priest in the Eleusinian mysteries (an ancient Greek ritual) More about that here: https://www.ancient.eu/article/32/the-eleusinian-mysteries-the-rites-of-demeter/
Number—5; represents the essence of things as they are; latin word quintessence; the number of senses we have; bridging the world between senses and meaning
Astrology—Taurus ♉ & Jupiter ♃
Crossed keys—the opening of new doors; keys of heaven held by St Peter
Triple Crown—authority and power; crown that rules the conscious, the subconscious & the super conscious
Key—symbolizes unlocking potential
Pillars—two pillars symbolizing law and liberty (or obedience/disobedience)
Pose—right hand connecting heaven & earth—blessing (same pose as the man on the 10 of swords); holding the cross of the pope in his left hand (religious scepter)
Cross of the pope—latin cross with 3 horizontal beams, the beams represent the pope’s three-fold rule as highest priest, highest teacher, and chief shepherd; it also symbolizes the pope is (as christ’s representative on earth) the co-ruler of three kingdoms: heaven, earth and hell.
Other figures in the card—followers kneeling to gain wisdom and insight that only the hierophant can give.
Tarot Cards: Hidden Symbols Explained book