16564609 has 4 divisors (see below), whose sum is σ = 16580016. Its totient is φ = 16549204.

The previous prime is 16564601. The next prime is 16564627. The reversal of 16564609 is 90646561.

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 16564609 - 2³ = 16564601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16564601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5959 + ... + 8284.

It is an arithmetic number, because the mean of its divisors is an integer number (4145004).

Almost surely, 2^16564609 is an apocalyptic number.

It is an amenable number.

16564609 is a deficient number, since it is larger than the sum of its proper divisors (15407).

16564609 is a wasteful number, since it uses less digits than its factorization.

16564609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15406.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 16564609 is about 4069.9642504572. The cubic root of 16564609 is about 254.9140245851.

The spelling of 16564609 in words is "sixteen million, five hundred sixty-four thousand, six hundred nine".