256999 has 4 divisors (see below), whose sum is σ = 258336. Its totient is φ = 255664.

The previous prime is 256981. The next prime is 257003. The reversal of 256999 is 999652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256999 - 2⁵ = 256967 is a prime.

It is a Duffinian number.

256999 is a modest number, since divided by 999 gives 256 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 319 + ... + 784.

It is an arithmetic number, because the mean of its divisors is an integer number (64584).

It is a Poulet number, since it divides 2²⁵⁶⁹⁹⁸-1.

2²⁵⁶⁹⁹⁹ is an apocalyptic number.

256999 is a deficient number, since it is larger than the sum of its proper divisors (1337).

256999 is a wasteful number, since it uses less digits than its factorization.

256999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336.

The product of its digits is 43740, while the sum is 40.

The square root of 256999 is about 506.9506879372. The cubic root of 256999 is about 63.5785293347.

The spelling of 256999 in words is "two hundred fifty-six thousand, nine hundred ninety-nine".