Atalanta (Ἀταλάντη) comes from the Greek atalantos, meaning "equal in weight" or "balanced." In Greek mythology, Atalanta is the hunter and athlete who would only marry a man who could outrun her in a footrace — and she could outrun any of them, until Hippomenes used golden apples to distract her.
Atalanta is rare as a girls' name today but has the dignity of a mythological athlete.
Atalanta 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 Atalanta reduce to 7, The Seeker. This is a traditional interpretive system, not a factual claim about the name.