Miriam (מִרְיָם) is the original Hebrew form of Mary — uncertain etymology, possibly "beloved" or "bitter sea" or from the Egyptian mr ("love"). Miriam Yeung, Miriam Margolyes — among modern Miriams.
Miriam does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Miriam reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.