561026861 has 4 divisors (see below), whose sum is σ = 561103872. Its totient is φ = 560949852.

The previous prime is 561026857. The next prime is 561026881. The reversal of 561026861 is 168620165.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 561026861 - 2² = 561026857 is a prime.

It is a super-2 number, since 2×561026861² = 629502277527026642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561026801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26285 + ... + 42578.

It is an arithmetic number, because the mean of its divisors is an integer number (140275968).

Almost surely, 2^561026861 is an apocalyptic number.

It is an amenable number.

561026861 is a deficient number, since it is larger than the sum of its proper divisors (77011).

561026861 is an equidigital number, since it uses as much as digits as its factorization.

561026861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77010.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 561026861 is about 23686.0055940211. The cubic root of 561026861 is about 824.7605603275.

The spelling of 561026861 in words is "five hundred sixty-one million, twenty-six thousand, eight hundred sixty-one".