561806689 has 2 divisors, whose sum is σ = 561806690. Its totient is φ = 561806688.

The previous prime is 561806677. The next prime is 561806711. The reversal of 561806689 is 986608165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398401600 + 163405089 = 19960^2 + 12783^2 .

It is a cyclic number.

It is not a de Polignac number, because 561806689 - 2⁵ = 561806657 is a prime.

It is not a weakly prime, because it can be changed into another prime (561801689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280903344 + 280903345.

It is an arithmetic number, because the mean of its divisors is an integer number (280903345).

Almost surely, 2^561806689 is an apocalyptic number.

It is an amenable number.

561806689 is a deficient number, since it is larger than the sum of its proper divisors (1).

561806689 is an equidigital number, since it uses as much as digits as its factorization.

561806689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 49.

The square root of 561806689 is about 23702.4616654051. The cubic root of 561806689 is about 825.1425227906.

The spelling of 561806689 in words is "five hundred sixty-one million, eight hundred six thousand, six hundred eighty-nine".