565509 has 12 divisors (see below), whose sum is σ = 877344. Its totient is φ = 323064.

The previous prime is 565507. The next prime is 565511. The reversal of 565509 is 905565.

565509 = 22² + 23² + ... + 119².

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (565507) and next prime (565511).

It is not a de Polignac number, because 565509 - 2¹ = 565507 is a prime.

It is an Ulam 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 565509.

It is not an unprimeable number, because it can be changed into a prime (565507) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1777 + ... + 2070.

It is an arithmetic number, because the mean of its divisors is an integer number (73112).

2⁵⁶⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

565509 is a deficient number, since it is larger than the sum of its proper divisors (311835).

565509 is a wasteful number, since it uses less digits than its factorization.

565509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864 (or 3857 counting only the distinct ones).

The product of its (nonzero) digits is 6750, while the sum is 30.

The square root of 565509 is about 752.0033244607. The cubic root of 565509 is about 82.6951121180.

It can be divided in two parts, 56 and 5509, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 565509 in words is "five hundred sixty-five thousand, five hundred nine".