561858 has 16 divisors (see below), whose sum is σ = 1226016. Its totient is φ = 170240.

The previous prime is 561839. The next prime is 561907. The reversal of 561858 is 858165.

It is a Harshad number since it is a multiple of its sum of digits (33).

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

It is a congruent number.

It is an unprimeable number.

561858 is an untouchable number, because it is not equal to the sum of proper divisors of any 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, 4191 + ... + 4322.

It is an arithmetic number, because the mean of its divisors is an integer number (76626).

2⁵⁶¹⁸⁵⁸ is an apocalyptic number.

561858 is an abundant number, since it is smaller than the sum of its proper divisors (664158).

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

561858 is a wasteful number, since it uses less digits than its factorization.

561858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8529.

The product of its digits is 9600, while the sum is 33.

The square root of 561858 is about 749.5718778076. The cubic root of 561858 is about 82.5167642700.

The spelling of 561858 in words is "five hundred sixty-one thousand, eight hundred fifty-eight".