565621 has 4 divisors (see below), whose sum is σ = 646432. Its totient is φ = 484812.

The previous prime is 565613. The next prime is 565637. The reversal of 565621 is 126565.

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.

It is a cyclic number.

It is not a de Polignac number, because 565621 - 2³ = 565613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 565621.

It is not an unprimeable number, because it can be changed into a prime (565651) 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, 40395 + ... + 40408.

It is an arithmetic number, because the mean of its divisors is an integer number (161608).

2⁵⁶⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

565621 is a deficient number, since it is larger than the sum of its proper divisors (80811).

565621 is an equidigital number, since it uses as much as digits as its factorization.

565621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80810.

The product of its digits is 1800, while the sum is 25.

The square root of 565621 is about 752.0777885299. The cubic root of 565621 is about 82.7005710592.

The spelling of 565621 in words is "five hundred sixty-five thousand, six hundred twenty-one".