256317 has 4 divisors (see below), whose sum is σ = 341760. Its totient is φ = 170876.

The previous prime is 256313. The next prime is 256337. The reversal of 256317 is 713652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256317 - 2² = 256313 is a prime.

It is a D-number.

256317 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256317.

It is not an unprimeable number, because it can be changed into a prime (256313) 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, 42717 + ... + 42722.

It is an arithmetic number, because the mean of its divisors is an integer number (85440).

2²⁵⁶³¹⁷ is an apocalyptic number.

It is an amenable number.

256317 is a deficient number, since it is larger than the sum of its proper divisors (85443).

256317 is an equidigital number, since it uses as much as digits as its factorization.

256317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85442.

The product of its digits is 1260, while the sum is 24.

The square root of 256317 is about 506.2775918407. The cubic root of 256317 is about 63.5222399211.

Adding to 256317 its reverse (713652), we get a palindrome (969969).

The spelling of 256317 in words is "two hundred fifty-six thousand, three hundred seventeen".