561858749 has 2 divisors, whose sum is σ = 561858750. Its totient is φ = 561858748.

The previous prime is 561858733. The next prime is 561858751. The reversal of 561858749 is 947858165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 509946724 + 51912025 = 22582^2 + 7205^2 .

It is a cyclic number.

It is not a de Polignac number, because 561858749 - 2⁴ = 561858733 is a prime.

It is a Sophie Germain prime.

Together with 561858751, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 561858749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561858149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280929374 + 280929375.

It is an arithmetic number, because the mean of its divisors is an integer number (280929375).

Almost surely, 2^561858749 is an apocalyptic number.

It is an amenable number.

561858749 is a deficient number, since it is larger than the sum of its proper divisors (1).

561858749 is an equidigital number, since it uses as much as digits as its factorization.

561858749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2419200, while the sum is 53.

The square root of 561858749 is about 23703.5598381340. The cubic root of 561858749 is about 825.1680093703.

The spelling of 561858749 in words is "five hundred sixty-one million, eight hundred fifty-eight thousand, seven hundred forty-nine".