The fiftieth of the seventy-two is Daniel, written in Hebrew exactly as the name of the biblical figure is written. As with Michael at forty-two, the coincidence is genuine rather than an artefact of English.
Daniel is a human being in the book that bears his name: a Judean at the Babylonian and Persian courts, an interpreter of dreams and visions, and the recipient of the apocalyptic material in the book's second half. He is not an angel; the angels in the book are Gabriel and Michael, who appear to him. The name itself means something like God is my judge and occurs elsewhere in the Hebrew Bible as an ordinary personal name.
Its appearance among the seventy-two is a consequence of the derivation rather than a reference to the prophet. The procedure yields three consonants; the suffix rule adds -el; the result is a name that already existed. Given how many Hebrew personal names are built on exactly this pattern, some of the seventy-two were bound to coincide with them.
This has one further implication worth drawing out. The seventy-two are not, in origin, characters. They have no stories, no biblical episodes, no dealings with anyone. They are positions in a sequence with names attached, and everything that makes them feel like individuals, an office, a virtue, a psalm, a birth-date window, a tarot card, was supplied later and supplied systematically, to all seventy-two at once.
That is the opposite of how Michael, Gabriel and Raphael acquired their identities, which came from narratives in which they act. The two kinds of angel are routinely tabulated together, and they are not the same kind of thing.