561685 has 4 divisors (see below), whose sum is σ = 674028. Its totient is φ = 449344.

The previous prime is 561667. The next prime is 561703. The reversal of 561685 is 586165.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (561667) and next prime (561703).

It can be written as a sum of positive squares in 2 ways, for example, as 352836 + 208849 = 594^2 + 457^2 .

It is a cyclic number.

It is not a de Polignac number, because 561685 - 2⁹ = 561173 is a prime.

It is a Duffinian number.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 56164 + ... + 56173.

It is an arithmetic number, because the mean of its divisors is an integer number (168507).

2⁵⁶¹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

561685 is a deficient number, since it is larger than the sum of its proper divisors (112343).

561685 is a wasteful number, since it uses less digits than its factorization.

561685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112342.

The product of its digits is 7200, while the sum is 31.

The square root of 561685 is about 749.4564697166. The cubic root of 561685 is about 82.5082942380.

The spelling of 561685 in words is "five hundred sixty-one thousand, six hundred eighty-five".