23409 has 15 divisors (see below), whose sum is σ = 37147. Its totient is φ = 14688.

The previous prime is 23399. The next prime is 23417. The reversal of 23409 is 90432.

23409 = T₁₅₂ + T₁₅₃.

23409 = 1³ + 2³ + ... + 17³.

The square root of 23409 is 153.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 18225 + 5184 = 135^2 + 72^2 .

It is not a de Polignac number, because 23409 - 2¹³ = 15217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 12.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 23391 and 23400.

It is not an unprimeable number, because it can be changed into a prime (23459) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1369 + ... + 1385.

2²³⁴⁰⁹ is an apocalyptic number.

23409 is the 153-rd square number.

23409 is the 77-th centered octagonal number.

It is an amenable number.

23409 is a deficient number, since it is larger than the sum of its proper divisors (13738).

23409 is an equidigital number, since it uses as much as digits as its factorization.

With its predecessor (23408) it forms an eRAP, since the sums of their prime factors are consecutive (45 and 46).

23409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The cubic root of 23409 is about 28.6062515879.

The spelling of 23409 in words is "twenty-three thousand, four hundred nine".