23999 has 4 divisors (see below), whose sum is σ = 24336. Its totient is φ = 23664.

The previous prime is 23993. The next prime is 24001. The reversal of 23999 is 99932.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 23999 - 2⁸ = 23743 is a prime.

It is a Duffinian number.

23999 is a modest number, since divided by 999 gives 23 as remainder.

It is a plaindrome in base 8 and base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14 + ... + 219.

It is an arithmetic number, because the mean of its divisors is an integer number (6084).

2²³⁹⁹⁹ is an apocalyptic number.

23999 is a deficient number, since it is larger than the sum of its proper divisors (337).

23999 is a wasteful number, since it uses less digits than its factorization.

23999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336.

The product of its digits is 4374, while the sum is 32.

The square root of 23999 is about 154.9161063286. The cubic root of 23999 is about 28.8445907757.

The spelling of 23999 in words is "twenty-three thousand, nine hundred ninety-nine".