23642809 has 4 divisors (see below), whose sum is σ = 23693904. Its totient is φ = 23591716.

The previous prime is 23642791. The next prime is 23642813. The reversal of 23642809 is 90824632.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 23642809 - 2⁵ = 23642777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23642849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24847 + ... + 25780.

It is an arithmetic number, because the mean of its divisors is an integer number (5923476).

Almost surely, 2^23642809 is an apocalyptic number.

It is an amenable number.

23642809 is a deficient number, since it is larger than the sum of its proper divisors (51095).

23642809 is an equidigital number, since it uses as much as digits as its factorization.

23642809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51094.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 23642809 is about 4862.3871709275. The cubic root of 23642809 is about 287.0117596059.

The spelling of 23642809 in words is "twenty-three million, six hundred forty-two thousand, eight hundred nine".