Ayn was chosen by Alisa Zinovyevna Rosenbaum (1905-1982) — born in St. Petersburg, Russia, immigrated to the United States in 1926 — when she renamed herself "Ayn Rand" upon arrival, taking "Ayn" reportedly from a Finnish writer (likely Aino Kallas) and "Rand" from her Remington-Rand typewriter. *Ayn Rand — American novelist and philosopher; founder of the philosophy of Objectivism; her two longest novels The Fountainhead (1943) and Atlas Shrugged (1957) have together sold over 25 million copies. A 1991 Library of Congress and Book-of-the-Month Club survey found Atlas Shrugged the second most-influential book in Americans' lives after the Bible. Her libertarian-individualist philosophy of rational self-interest has had wide influence in American conservative and libertarian thought; advocates have included Alan Greenspan and Paul Ryan. Ayn Rand Institute founded after her death*.
Subject of Anne Heller's Ayn Rand and the World She Made (2009) and Jennifer Burns's Goddess of the Market (2009).
Ayn 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 Ayn reduce to 4, The Builder. This is a traditional interpretive system, not a factual claim about the name.