256297557 has 16 divisors (see below), whose sum is σ = 353748992. Its totient is φ = 164928960.

The previous prime is 256297543. The next prime is 256297577. The reversal of 256297557 is 755792652.

It is not a de Polignac number, because 256297557 - 2⁴ = 256297541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256297577) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5007 + ... + 23187.

It is an arithmetic number, because the mean of its divisors is an integer number (22109312).

Almost surely, 2^256297557 is an apocalyptic number.

It is an amenable number.

256297557 is a deficient number, since it is larger than the sum of its proper divisors (97451435).

256297557 is a wasteful number, since it uses less digits than its factorization.

256297557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18348.

The product of its digits is 1323000, while the sum is 48.

The square root of 256297557 is about 16009.2959557877. The cubic root of 256297557 is about 635.2063371449.

The spelling of 256297557 in words is "two hundred fifty-six million, two hundred ninety-seven thousand, five hundred fifty-seven".