561906 has 48 divisors (see below), whose sum is σ = 1347840. Its totient is φ = 168480.

The previous prime is 561839. The next prime is 561907. The reversal of 561906 is 609165.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 561906.

It is not an unprimeable number, because it can be changed into a prime (561907) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10576 + ... + 10628.

It is an arithmetic number, because the mean of its divisors is an integer number (28080).

2⁵⁶¹⁹⁰⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (673920).

561906 is an abundant number, since it is smaller than the sum of its proper divisors (785934).

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

561906 is a wasteful number, since it uses less digits than its factorization.

561906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 561906 is about 749.6038954008. The cubic root of 561906 is about 82.5191140285.

The spelling of 561906 in words is "five hundred sixty-one thousand, nine hundred six".