561881 has 8 divisors (see below), whose sum is σ = 586080. Its totient is φ = 538272.

The previous prime is 561839. The next prime is 561907. The reversal of 561881 is 188165.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 561881 - 2¹⁴ = 545497 is a prime.

It is a super-2 number, since 2×561881² = 631420516322, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 561881.

It is not an unprimeable number, because it can be changed into a prime (561181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3050 + ... + 3228.

It is an arithmetic number, because the mean of its divisors is an integer number (73260).

2⁵⁶¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

561881 is a deficient number, since it is larger than the sum of its proper divisors (24199).

561881 is a wasteful number, since it uses less digits than its factorization.

561881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295.

The product of its digits is 1920, while the sum is 29.

The square root of 561881 is about 749.5872197416. The cubic root of 561881 is about 82.5178902126.

The spelling of 561881 in words is "five hundred sixty-one thousand, eight hundred eighty-one".