Alma is from the Latin almus (nourishing, kindly) — also the Spanish alma (soul). Alma Mater — the Latin phrase meaning "nourishing mother" — refers to one's university or school; used universally across English-speaking academic culture. Alma Schindler — Alma Mahler's maiden name.
Alma 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 Alma reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.