564721 has 4 divisors (see below), whose sum is σ = 566244. Its totient is φ = 563200.

The previous prime is 564713. The next prime is 564761. The reversal of 564721 is 127465.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 314721 + 250000 = 561^2 + 500^2 .

It is a cyclic number.

It is not a de Polignac number, because 564721 - 2³ = 564713 is a prime.

It is a Duffinian number.

564721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (564701) 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, 201 + ... + 1081.

It is an arithmetic number, because the mean of its divisors is an integer number (141561).

2⁵⁶⁴⁷²¹ is an apocalyptic number.

It is an amenable number.

564721 is a deficient number, since it is larger than the sum of its proper divisors (1523).

564721 is an equidigital number, since it uses as much as digits as its factorization.

564721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522.

The product of its digits is 1680, while the sum is 25.

The square root of 564721 is about 751.4792079625. The cubic root of 564721 is about 82.6566841773.

The spelling of 564721 in words is "five hundred sixty-four thousand, seven hundred twenty-one".