256000399 has 8 divisors (see below), whose sum is σ = 276827328. Its totient is φ = 235814400.

The previous prime is 256000391. The next prime is 256000403. The reversal of 256000399 is 993000652.

It is a happy number.

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 256000399 - 2³ = 256000391 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 (256000391) 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 7 ways as a sum of consecutive naturals, for example, 159402 + ... + 160999.

It is an arithmetic number, because the mean of its divisors is an integer number (34603416).

Almost surely, 2^256000399 is an apocalyptic number.

256000399 is a deficient number, since it is larger than the sum of its proper divisors (20826929).

256000399 is a wasteful number, since it uses less digits than its factorization.

256000399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320465.

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 256000399 is about 16000.0124687451. The cubic root of 256000399 is about 634.9607506689.

The spelling of 256000399 in words is "two hundred fifty-six million, three hundred ninety-nine", and thus it is an aban number.