561556 has 24 divisors (see below), whose sum is σ = 1048320. Its totient is φ = 262752.

The previous prime is 561553. The next prime is 561559. The reversal of 561556 is 655165.

It is an interprime number because it is at equal distance from previous prime (561553) and next prime (561559).

It is a super-2 number, since 2×561556² = 630690282272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561551) by changing a digit.

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, 5401 + ... + 5503.

It is an arithmetic number, because the mean of its divisors is an integer number (43680).

2⁵⁶¹⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

561556 is a deficient number, since it is larger than the sum of its proper divisors (486764).

561556 is a wasteful number, since it uses less digits than its factorization.

561556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183 (or 181 counting only the distinct ones).

The product of its digits is 4500, while the sum is 28.

The square root of 561556 is about 749.3704024046. The cubic root of 561556 is about 82.5019773019.

It can be divided in two parts, 5615 and 56, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 561556 in words is "five hundred sixty-one thousand, five hundred fifty-six".