23509213 has 16 divisors (see below), whose sum is σ = 30459520. Its totient is φ = 17620416.

The previous prime is 23509193. The next prime is 23509219. The reversal of 23509213 is 31290532.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23509213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23509219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5070 + ... + 8527.

It is an arithmetic number, because the mean of its divisors is an integer number (1903720).

Almost surely, 2^23509213 is an apocalyptic number.

It is an amenable number.

23509213 is a deficient number, since it is larger than the sum of its proper divisors (6950307).

23509213 is a wasteful number, since it uses less digits than its factorization.

23509213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13636.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 23509213 is about 4848.6300126943. The cubic root of 23509213 is about 286.4701421797.

Adding to 23509213 its reverse (31290532), we get a palindrome (54799745).

The spelling of 23509213 in words is "twenty-three million, five hundred nine thousand, two hundred thirteen".