256887515 has 8 divisors (see below), whose sum is σ = 308386608. Its totient is φ = 205428960.

The previous prime is 256887487. The next prime is 256887517. The reversal of 256887515 is 515788652.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256887515 - 2⁶ = 256887451 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 256887515.

It is not an unprimeable number, because it can be changed into a prime (256887517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6209 + ... + 23501.

It is an arithmetic number, because the mean of its divisors is an integer number (38548326).

Almost surely, 2^256887515 is an apocalyptic number.

256887515 is a deficient number, since it is larger than the sum of its proper divisors (51499093).

256887515 is a wasteful number, since it uses less digits than its factorization.

256887515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20269.

The product of its digits is 672000, while the sum is 47.

The square root of 256887515 is about 16027.7108471547. The cubic root of 256887515 is about 635.6933464586.

The spelling of 256887515 in words is "two hundred fifty-six million, eight hundred eighty-seven thousand, five hundred fifteen".