Number 21 — Twenty-one

The number 21 is written with one or two Western digits from the Hindu–Arabic numeral system. It is odd and composite. Its positive divisors are 1, 3, 7, 21. Additional properties include being a triangular number and a Fibonacci number. These mathematical properties are verifiable; religious, esoteric, and numerological readings depend on a particular tradition and are not properties of the number itself. Numerological reading: the number is associated with maturity, synthesis, and a completed cycle. In a talismanic or meditative composition it may express an intention to focus on these qualities; meanings vary by school and context.