561728889 has 6 divisors (see below), whose sum is σ = 811386186. Its totient is φ = 374485920.

The previous prime is 561728879. The next prime is 561728891. The reversal of 561728889 is 988827165.

561728889 is a `hidden beast` number, since 561 + 72 + 8 + 8 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 498048489 + 63680400 = 22317^2 + 7980^2 .

It is not a de Polignac number, because 561728889 - 2¹⁹ = 561204601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561728879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 31207152 + ... + 31207169.

It is an arithmetic number, because the mean of its divisors is an integer number (135231031).

Almost surely, 2^561728889 is an apocalyptic number.

It is an amenable number.

561728889 is a deficient number, since it is larger than the sum of its proper divisors (249657297).

561728889 is a wasteful number, since it uses less digits than its factorization.

561728889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62414327 (or 62414324 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The square root of 561728889 is about 23700.8204288375. The cubic root of 561728889 is about 825.1044319591.

The spelling of 561728889 in words is "five hundred sixty-one million, seven hundred twenty-eight thousand, eight hundred eighty-nine".