256246581 has 16 divisors (see below), whose sum is σ = 356040000. Its totient is φ = 163728768.

The previous prime is 256246537. The next prime is 256246591. The reversal of 256246581 is 185642652.

It is not a de Polignac number, because 256246581 - 2²² = 252052277 is a prime.

It is a super-2 number, since 2×256246581² = 131324620548379122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256246511) 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, 1170 + ... + 22668.

It is an arithmetic number, because the mean of its divisors is an integer number (22252500).

Almost surely, 2^256246581 is an apocalyptic number.

It is an amenable number.

256246581 is a deficient number, since it is larger than the sum of its proper divisors (99793419).

256246581 is a wasteful number, since it uses less digits than its factorization.

256246581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21668.

The product of its digits is 115200, while the sum is 39.

The square root of 256246581 is about 16007.7038016075. The cubic root of 256246581 is about 635.1642214811.

The spelling of 256246581 in words is "two hundred fifty-six million, two hundred forty-six thousand, five hundred eighty-one".