565561 has 4 divisors (see below), whose sum is σ = 572800. Its totient is φ = 558324.

The previous prime is 565559. The next prime is 565567. The reversal of 565561 is 165565.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165565 = 5 ⋅33113.

It is a cyclic number.

It is not a de Polignac number, because 565561 - 2¹ = 565559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (565567) 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, 3501 + ... + 3658.

It is an arithmetic number, because the mean of its divisors is an integer number (143200).

2⁵⁶⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

565561 is a deficient number, since it is larger than the sum of its proper divisors (7239).

565561 is an equidigital number, since it uses as much as digits as its factorization.

565561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7238.

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

The square root of 565561 is about 752.0378979812. The cubic root of 565561 is about 82.6976467161.

The spelling of 565561 in words is "five hundred sixty-five thousand, five hundred sixty-one".