Mimi is a diminutive of Maria, Miriam, or Wilhelmina — used as a standalone given name. Mimi in La Bohème — Giacomo Puccini's iconic 1896 opera; the consumptive seamstress Mimi falls in love with the poet Rodolfo in their Latin Quarter Parisian garret; her aria "Mi chiamano Mimì" ("They call me Mimi") is among the most-celebrated soprano arias in the operatic repertoire; La Bohème is the most-performed opera in the world after Verdi's Aida and Mozart's The Magic Flute; inspired Jonathan Larson's musical Rent (1996) — winner of the Pulitzer Prize for Drama and four Tony Awards. Mariah Carey's nickname since the 1990s is "Mimi" — her 2005 album The Emancipation of Mimi sold 12+ million copies worldwide and produced "We Belong Together" — the #1 song of the 2000s on the Billboard Hot 100.
Mimi 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 Mimi reduce to 8, The Visionary. This is a traditional interpretive system, not a factual claim about the name.