256206515 has 4 divisors (see below), whose sum is σ = 307447824. Its totient is φ = 204965208.

The previous prime is 256206487. The next prime is 256206529. The reversal of 256206515 is 515602652.

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

It is a cyclic number.

It is not a de Polignac number, because 256206515 - 2⁶ = 256206451 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25620647 + ... + 25620656.

It is an arithmetic number, because the mean of its divisors is an integer number (76861956).

Almost surely, 2^256206515 is an apocalyptic number.

256206515 is a deficient number, since it is larger than the sum of its proper divisors (51241309).

256206515 is an equidigital number, since it uses as much as digits as its factorization.

256206515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51241308.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 256206515 is about 16006.4522927474. The cubic root of 256206515 is about 635.1311155875.

The spelling of 256206515 in words is "two hundred fifty-six million, two hundred six thousand, five hundred fifteen".