515865 has 32 divisors (see below), whose sum is σ = 1002240. Its totient is φ = 221952.

The previous prime is 515861. The next prime is 515873. The reversal of 515865 is 568515.

It is a happy number.

It is not a de Polignac number, because 515865 - 2² = 515861 is a prime.

It is a super-2 number, since 2×515865² = 532233396450, which contains 22 as substring.

It is a Curzon 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 515865.

It is not an unprimeable number, because it can be changed into a prime (515861) 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 31 ways as a sum of consecutive naturals, for example, 30337 + ... + 30353.

It is an arithmetic number, because the mean of its divisors is an integer number (31320).

2⁵¹⁵⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

515865 is a deficient number, since it is larger than the sum of its proper divisors (486375).

515865 is an equidigital number, since it uses as much as digits as its factorization.

515865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 32 counting only the distinct ones).

The product of its digits is 6000, while the sum is 30.

The square root of 515865 is about 718.2374259254. The cubic root of 515865 is about 80.2007976654.

Subtracting 515865 from its reverse (568515), we obtain a triangular number (52650 = T₃₂₄).

The spelling of 515865 in words is "five hundred fifteen thousand, eight hundred sixty-five".