23709 has 8 divisors (see below), whose sum is σ = 36160. Its totient is φ = 13536.

The previous prime is 23689. The next prime is 23719. The reversal of 23709 is 90732.

23709 is nontrivially palindromic in base 2.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 23709 - 2⁵ = 23677 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1129 = 23709 / (2 + 3 + 7 + 0 + 9).

It is a Duffinian number.

It is a Curzon number.

23709 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 23709.

It is not an unprimeable number, because it can be changed into a prime (23719) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 544 + ... + 585.

It is an arithmetic number, because the mean of its divisors is an integer number (4520).

2²³⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

23709 is a deficient number, since it is larger than the sum of its proper divisors (12451).

23709 is a wasteful number, since it uses less digits than its factorization.

23709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139.

The product of its (nonzero) digits is 378, while the sum is 21.

The square root of 23709 is about 153.9772710500. The cubic root of 23709 is about 28.7279351811.

The spelling of 23709 in words is "twenty-three thousand, seven hundred nine".