11999

11999 is a natural number that follows 11998 and precedes 12000. In decimal notation it is written as 11999. It is an odd, composite five-digit integer.

In mathematics, 11999 factors as 13^2 × 71. This gives it six positive divisors: 1, 13, 71, 169, 923, and 11999. The digital root of 11999 is 2 (the sum of its digits is 29, which reduces to 11, then to 2). It is not a perfect square, and its square root is approximately 109.54. In binary, 11999 is 10111011011111₂.

11999 has no widely noted historical significance as a year in the common historical record. In general use, it may appear as a numerical identifier, a catalog number, or a placeholder in puzzles and examples. As a five-digit integer with a repeated prime factor, it can serve as an illustrative case in discussions of prime factorization, divisors, and base representations.

Related concepts include prime factorization, divisor count, and base conversions. The number also exemplifies a case where multiplication of a square of one prime by another prime yields a composite with a modest number of divisors.