256257155 has 16 divisors (see below), whose sum is σ = 383387904. Its totient is φ = 159744480.

The previous prime is 256257151. The next prime is 256257163. The reversal of 256257155 is 551752652.

It is not a de Polignac number, because 256257155 - 2² = 256257151 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256257151) 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 15 ways as a sum of consecutive naturals, for example, 332417 + ... + 333186.

It is an arithmetic number, because the mean of its divisors is an integer number (23961744).

Almost surely, 2^256257155 is an apocalyptic number.

256257155 is a deficient number, since it is larger than the sum of its proper divisors (127130749).

256257155 is a wasteful number, since it uses less digits than its factorization.

256257155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 665626.

The product of its digits is 105000, while the sum is 38.

The square root of 256257155 is about 16008.0340766754. The cubic root of 256257155 is about 635.1729580323.

The spelling of 256257155 in words is "two hundred fifty-six million, two hundred fifty-seven thousand, one hundred fifty-five".