564991 has 4 divisors (see below), whose sum is σ = 645712. Its totient is φ = 484272.

The previous prime is 564989. The next prime is 564997. The reversal of 564991 is 199465.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 564991 - 2¹ = 564989 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (564997) 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, 40350 + ... + 40363.

It is an arithmetic number, because the mean of its divisors is an integer number (161428).

2⁵⁶⁴⁹⁹¹ is an apocalyptic number.

564991 is a deficient number, since it is larger than the sum of its proper divisors (80721).

564991 is an equidigital number, since it uses as much as digits as its factorization.

564991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80720.

The product of its digits is 9720, while the sum is 34.

The square root of 564991 is about 751.6588321839. The cubic root of 564991 is about 82.6698551349.

The spelling of 564991 in words is "five hundred sixty-four thousand, nine hundred ninety-one".