520665 has 16 divisors (see below), whose sum is σ = 843648. Its totient is φ = 274176.

The previous prime is 520649. The next prime is 520679. The reversal of 520665 is 566025.

It is not a de Polignac number, because 520665 - 2⁴ = 520649 is a prime.

It is a nialpdrome in base 15.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1377 + ... + 1713.

It is an arithmetic number, because the mean of its divisors is an integer number (52728).

2⁵²⁰⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

520665 is a deficient number, since it is larger than the sum of its proper divisors (322983).

520665 is a wasteful number, since it uses less digits than its factorization.

520665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 520665 is about 721.5712023079. The cubic root of 520665 is about 80.4487798340.

The spelling of 520665 in words is "five hundred twenty thousand, six hundred sixty-five".