561555613 has 2 divisors, whose sum is σ = 561555614. Its totient is φ = 561555612.

The previous prime is 561555593. The next prime is 561555637. The reversal of 561555613 is 316555165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 494528644 + 67026969 = 22238^2 + 8187^2 .

It is a cyclic number.

It is not a de Polignac number, because 561555613 - 2²⁹ = 24684701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561556613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280777806 + 280777807.

It is an arithmetic number, because the mean of its divisors is an integer number (280777807).

Almost surely, 2^561555613 is an apocalyptic number.

It is an amenable number.

561555613 is a deficient number, since it is larger than the sum of its proper divisors (1).

561555613 is an equidigital number, since it uses as much as digits as its factorization.

561555613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 67500, while the sum is 37.

The square root of 561555613 is about 23697.1646616214. The cubic root of 561555613 is about 825.0195834960.

The spelling of 561555613 in words is "five hundred sixty-one million, five hundred fifty-five thousand, six hundred thirteen".