564831661 has 4 divisors (see below), whose sum is σ = 564920892. Its totient is φ = 564742432.

The previous prime is 564831623. The next prime is 564831691. The reversal of 564831661 is 166138465.

564831661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166138465 = 5 ⋅33227693.

It can be written as a sum of positive squares in 2 ways, for example, as 302586025 + 262245636 = 17395^2 + 16194^2 .

It is a cyclic number.

It is not a de Polignac number, because 564831661 - 2¹¹ = 564829613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (564831691) 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, 34330 + ... + 48043.

It is an arithmetic number, because the mean of its divisors is an integer number (141230223).

Almost surely, 2^564831661 is an apocalyptic number.

It is an amenable number.

564831661 is a deficient number, since it is larger than the sum of its proper divisors (89231).

564831661 is an equidigital number, since it uses as much as digits as its factorization.

564831661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89230.

The product of its digits is 103680, while the sum is 40.

The square root of 564831661 is about 23766.1873467328. The cubic root of 564831661 is about 826.6208287503.

The spelling of 564831661 in words is "five hundred sixty-four million, eight hundred thirty-one thousand, six hundred sixty-one".