561840 has 40 divisors (see below), whose sum is σ = 1742448. Its totient is φ = 149760.

The previous prime is 561839. The next prime is 561907. The reversal of 561840 is 48165.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 561840.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 561840.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 931 + ... + 1410.

2⁵⁶¹⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

561840 is an abundant number, since it is smaller than the sum of its proper divisors (1180608).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561840 is a wasteful number, since it uses less digits than its factorization.

561840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2357 (or 2351 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 561840 is about 749.5598708576. The cubic root of 561840 is about 82.5158830760.

The spelling of 561840 in words is "five hundred sixty-one thousand, eight hundred forty".