561863 has 4 divisors (see below), whose sum is σ = 567528. Its totient is φ = 556200.

The previous prime is 561839. The next prime is 561907. The reversal of 561863 is 368165.

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

It is a cyclic number.

It is not a de Polignac number, because 561863 - 2⁸ = 561607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (560863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2681 + ... + 2882.

It is an arithmetic number, because the mean of its divisors is an integer number (141882).

2⁵⁶¹⁸⁶³ is an apocalyptic number.

561863 is a deficient number, since it is larger than the sum of its proper divisors (5665).

561863 is a wasteful number, since it uses less digits than its factorization.

561863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5664.

The product of its digits is 4320, while the sum is 29.

The square root of 561863 is about 749.5752130374. The cubic root of 561863 is about 82.5170090427.

The spelling of 561863 in words is "five hundred sixty-one thousand, eight hundred sixty-three".