Mikayla is the modern American feminine of Michael — from the Hebrew Mīkhā'ēl ("who is like God?"). Mikayla Johnson — American gymnast. The biblical Michael is one of the seven archangels in Judaism, Christianity, and Islam, often depicted as the leader of God's army in apocalyptic literature (Revelation 12:7-9). The Hebrew form Michal appears in 1 Samuel as Saul's daughter and David's first wife. Mikayla (spelling) was the most-popular variant in the early 2000s alongside Michaela.
Mikayla 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 Mikayla reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.