561810 has 32 divisors (see below), whose sum is σ = 1374912. Its totient is φ = 146880.

The previous prime is 561809. The next prime is 561829. The reversal of 561810 is 18165.

It is a super-3 number, since 3×561810³ = 531973073333223000, which contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is a Curzon number.

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 15 ways as a sum of consecutive naturals, for example, 1677 + ... + 1983.

It is an arithmetic number, because the mean of its divisors is an integer number (42966).

2⁵⁶¹⁸¹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (687456).

561810 is an abundant number, since it is smaller than the sum of its proper divisors (813102).

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

561810 is a wasteful number, since it uses less digits than its factorization.

561810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378.

The product of its (nonzero) digits is 240, while the sum is 21.

The square root of 561810 is about 749.5398588467. The cubic root of 561810 is about 82.5144143776.

Adding to 561810 its reverse (18165), we get a palindrome (579975).

The spelling of 561810 in words is "five hundred sixty-one thousand, eight hundred ten".