256251657 has 8 divisors (see below), whose sum is σ = 341770176. Its totient is φ = 170783792.

The previous prime is 256251649. The next prime is 256251679. The reversal of 256251657 is 756152652.

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

It is a cyclic number.

It is not a de Polignac number, because 256251657 - 2³ = 256251649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256251607) 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 7 ways as a sum of consecutive naturals, for example, 1363 + ... + 22679.

It is an arithmetic number, because the mean of its divisors is an integer number (42721272).

Almost surely, 2^256251657 is an apocalyptic number.

It is an amenable number.

256251657 is a deficient number, since it is larger than the sum of its proper divisors (85518519).

256251657 is a wasteful number, since it uses less digits than its factorization.

256251657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25327.

The product of its digits is 126000, while the sum is 39.

The square root of 256251657 is about 16007.8623494831. The cubic root of 256251657 is about 635.1684154523.

The spelling of 256251657 in words is "two hundred fifty-six million, two hundred fifty-one thousand, six hundred fifty-seven".