256187888639 has 8 divisors (see below), whose sum is σ = 256776532368. Its totient is φ = 255599746560.

The previous prime is 256187888623. The next prime is 256187888657. The reversal of 256187888639 is 936888781652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256187888639 - 2⁴ = 256187888623 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 (256187888669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 906869 + ... + 1155329.

It is an arithmetic number, because the mean of its divisors is an integer number (32097066546).

Almost surely, 2^256187888639 is an apocalyptic number.

256187888639 is a deficient number, since it is larger than the sum of its proper divisors (588643729).

256187888639 is a wasteful number, since it uses less digits than its factorization.

256187888639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250825.

The product of its digits is 278691840, while the sum is 71.

The spelling of 256187888639 in words is "two hundred fifty-six billion, one hundred eighty-seven million, eight hundred eighty-eight thousand, six hundred thirty-nine".