561728879 has 2 divisors, whose sum is σ = 561728880. Its totient is φ = 561728878.

The previous prime is 561728861. The next prime is 561728891. The reversal of 561728879 is 978827165.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 561728879 - 2²⁰ = 560680303 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 561728879.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561778879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280864439 + 280864440.

It is an arithmetic number, because the mean of its divisors is an integer number (280864440).

Almost surely, 2^561728879 is an apocalyptic number.

561728879 is a deficient number, since it is larger than the sum of its proper divisors (1).

561728879 is an equidigital number, since it uses as much as digits as its factorization.

561728879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1693440, while the sum is 53.

The square root of 561728879 is about 23700.8202178743. The cubic root of 561728879 is about 825.1044270629.

The spelling of 561728879 in words is "five hundred sixty-one million, seven hundred twenty-eight thousand, eight hundred seventy-nine".