564505721 has 16 divisors (see below), whose sum is σ = 638668800. Its totient is φ = 495042240.

The previous prime is 564505717. The next prime is 564505769. The reversal of 564505721 is 127505465.

564505721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 564505721 - 2² = 564505717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (564505021) 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, 38216 + ... + 50886.

It is an arithmetic number, because the mean of its divisors is an integer number (39916800).

Almost surely, 2^564505721 is an apocalyptic number.

It is an amenable number.

564505721 is a deficient number, since it is larger than the sum of its proper divisors (74163079).

564505721 is a wasteful number, since it uses less digits than its factorization.

564505721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12856.

The product of its (nonzero) digits is 42000, while the sum is 35.

The square root of 564505721 is about 23759.3291361520. The cubic root of 564505721 is about 826.4617957419.

The spelling of 564505721 in words is "five hundred sixty-four million, five hundred five thousand, seven hundred twenty-one".