23209 has 2 divisors, whose sum is σ = 23210. Its totient is φ = 23208.

The previous prime is 23203. The next prime is 23227. The reversal of 23209 is 90232.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21609 + 1600 = 147^2 + 40^2 .

It is a cyclic number.

It is not a de Polignac number, because 23209 - 2³ = 23201 is a prime.

It is a plaindrome in base 7.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 23192 and 23201.

It is not a weakly prime, because it can be changed into another prime (23201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11604 + 11605.

It is an arithmetic number, because the mean of its divisors is an integer number (11605).

2²³²⁰⁹ is an apocalyptic number.

It is an amenable number.

23209 is a deficient number, since it is larger than the sum of its proper divisors (1).

23209 is an equidigital number, since it uses as much as digits as its factorization.

23209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 23209 is about 152.3450032000. The cubic root of 23209 is about 28.5245505087.

It can be divided in two parts, 23 and 209, that added together give a palindrome (232).

The spelling of 23209 in words is "twenty-three thousand, two hundred nine".