256506013 has 16 divisors (see below), whose sum is σ = 277482240. Its totient is φ = 236238336.

The previous prime is 256506007. The next prime is 256506043. The reversal of 256506013 is 310605652.

It is a cyclic number.

It is not a de Polignac number, because 256506013 - 2¹³ = 256497821 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 (256506043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171756 + ... + 173242.

It is an arithmetic number, because the mean of its divisors is an integer number (17342640).

Almost surely, 2^256506013 is an apocalyptic number.

It is an amenable number.

256506013 is a deficient number, since it is larger than the sum of its proper divisors (20976227).

256506013 is a wasteful number, since it uses less digits than its factorization.

256506013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 256506013 is about 16015.8050999630. The cubic root of 256506013 is about 635.3785025131.

The spelling of 256506013 in words is "two hundred fifty-six million, five hundred six thousand, thirteen".