520565 has 4 divisors (see below), whose sum is σ = 624684. Its totient is φ = 416448.

The previous prime is 520549. The next prime is 520567. The reversal of 520565 is 565025.

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

It can be written as a sum of positive squares in 2 ways, for example, as 139876 + 380689 = 374^2 + 617^2 .

It is a cyclic number.

It is not a de Polignac number, because 520565 - 2⁴ = 520549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 520565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52052 + ... + 52061.

It is an arithmetic number, because the mean of its divisors is an integer number (156171).

2⁵²⁰⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

520565 is a deficient number, since it is larger than the sum of its proper divisors (104119).

520565 is a wasteful number, since it uses less digits than its factorization.

520565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104118.

The product of its (nonzero) digits is 1500, while the sum is 23.

The square root of 520565 is about 721.5019057494. The cubic root of 520565 is about 80.4436291177.

The spelling of 520565 in words is "five hundred twenty thousand, five hundred sixty-five".