23011209 has 45 divisors (see below), whose sum is σ = 38152389. Its totient is φ = 13815360.

The previous prime is 23011189. The next prime is 23011211. The reversal of 23011209 is 90211032.

It is a happy number.

The square root of 23011209 is 4797.

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

It can be written as a sum of positive squares in 4 ways, for example, as 15327225 + 7683984 = 3915^2 + 2772^2 .

It is a de Polignac number, because none of the positive numbers 2^k-23011209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 23011191 and 23011200.

It is not an unprimeable number, because it can be changed into a prime (23011229) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 561229 + ... + 561269.

Almost surely, 2^23011209 is an apocalyptic number.

23011209 is the 4797-th square number.

23011209 is the 2399-th centered octagonal number.

It is an amenable number.

23011209 is a deficient number, since it is larger than the sum of its proper divisors (15141180).

23011209 is an equidigital number, since it uses as much as digits as its factorization.

23011209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The cubic root of 23011209 is about 284.4328888953.

It can be divided in two parts, 23011 and 209, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 23011209 in words is "twenty-three million, eleven thousand, two hundred nine".