Ildikó comes from the Germanic hild (battle) — Hildiko was the Germanic princess whom Attila the Hun married in 453 CE.
Ildikó is widely used in Hungary.
Ildikó 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 Ildikó reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.