256983 has 4 divisors (see below), whose sum is σ = 342648. Its totient is φ = 171320.

The previous prime is 256981. The next prime is 257003. The reversal of 256983 is 389652.

It is a happy number.

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 256983 - 2¹ = 256981 is a prime.

It is a D-number.

It is an alternating number because its digits alternate between even and odd.

256983 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256981) 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, 42828 + ... + 42833.

It is an arithmetic number, because the mean of its divisors is an integer number (85662).

2²⁵⁶⁹⁸³ is an apocalyptic number.

256983 is a deficient number, since it is larger than the sum of its proper divisors (85665).

256983 is an equidigital number, since it uses as much as digits as its factorization.

256983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85664.

The product of its digits is 12960, while the sum is 33.

The square root of 256983 is about 506.9349070640. The cubic root of 256983 is about 63.5772099034.

The spelling of 256983 in words is "two hundred fifty-six thousand, nine hundred eighty-three".