16564401 has 18 divisors (see below), whose sum is σ = 27833442. Its totient is φ = 9465120.

The previous prime is 16564397. The next prime is 16564411. The reversal of 16564401 is 10446561.

16564401 is a `hidden beast` number, since 1 + 656 + 4 + 4 + 0 + 1 = 666.

16564401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 10732176 + 5832225 = 3276^2 + 2415^2 .

It is not a de Polignac number, because 16564401 - 2² = 16564397 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16564411) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 18340 + ... + 19221.

Almost surely, 2^16564401 is an apocalyptic number.

It is an amenable number.

16564401 is a deficient number, since it is larger than the sum of its proper divisors (11269041).

16564401 is a wasteful number, since it uses less digits than its factorization.

16564401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37581 (or 37571 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 16564401 is about 4069.9386973270. The cubic root of 16564401 is about 254.9129576047.

The spelling of 16564401 in words is "sixteen million, five hundred sixty-four thousand, four hundred one".