256515 has 24 divisors (see below), whose sum is σ = 478800. Its totient is φ = 116928.

The previous prime is 256499. The next prime is 256517. The reversal of 256515 is 515652.

256515 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256515 - 2⁴ = 256499 is a prime.

256515 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256515.

It is not an unprimeable number, because it can be changed into a prime (256517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 561 + ... + 909.

It is an arithmetic number, because the mean of its divisors is an integer number (19950).

2²⁵⁶⁵¹⁵ is an apocalyptic number.

256515 is a deficient number, since it is larger than the sum of its proper divisors (222285).

256515 is a wasteful number, since it uses less digits than its factorization.

256515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371 (or 364 counting only the distinct ones).

The product of its digits is 1500, while the sum is 24.

The square root of 256515 is about 506.4730989895. The cubic root of 256515 is about 63.5385922846.

The spelling of 256515 in words is "two hundred fifty-six thousand, five hundred fifteen".