Iman (إيمان) is the Arabic word for "faith" — one of the concepts of Islamic spirituality.
Iman Abdulmajid (born 1955) is the Somali-American supermodel, philanthropist, and David Bowie's late wife.
Iman 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 Iman reduce to 1, The Leader. This is a traditional interpretive system, not a factual claim about the name.