23257509 has 24 divisors (see below), whose sum is σ = 34560288. Its totient is φ = 13796640.

The previous prime is 23257499. The next prime is 23257511. The reversal of 23257509 is 90575232.

It is not a de Polignac number, because 23257509 - 2⁵ = 23257477 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a self number, because there is not a number n which added to its sum of digits gives 23257509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23257529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 148059 + ... + 148215.

It is an arithmetic number, because the mean of its divisors is an integer number (1440012).

Almost surely, 2^23257509 is an apocalyptic number.

It is an amenable number.

23257509 is a deficient number, since it is larger than the sum of its proper divisors (11302779).

23257509 is a wasteful number, since it uses less digits than its factorization.

23257509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 33.

The square root of 23257509 is about 4822.6039646647. The cubic root of 23257509 is about 285.4440967996. Note that the first 3 decimals are identical.

The spelling of 23257509 in words is "twenty-three million, two hundred fifty-seven thousand, five hundred nine".