256581767 has 16 divisors (see below), whose sum is σ = 290293248. Its totient is φ = 225007200.

The previous prime is 256581739. The next prime is 256581797. The reversal of 256581767 is 767185652.

It is a cyclic number.

It is not a de Polignac number, because 256581767 - 2¹⁴ = 256565383 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 (256581707) 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, 42308 + ... + 47990.

It is an arithmetic number, because the mean of its divisors is an integer number (18143328).

Almost surely, 2^256581767 is an apocalyptic number.

256581767 is a deficient number, since it is larger than the sum of its proper divisors (33711481).

256581767 is a wasteful number, since it uses less digits than its factorization.

256581767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5870.

The product of its digits is 705600, while the sum is 47.

The square root of 256581767 is about 16018.1699017085. The cubic root of 256581767 is about 635.4410451997.

The spelling of 256581767 in words is "two hundred fifty-six million, five hundred eighty-one thousand, seven hundred sixty-seven".