256819 has 4 divisors (see below), whose sum is σ = 271944. Its totient is φ = 241696.

The previous prime is 256813. The next prime is 256831. The reversal of 256819 is 918652.

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 256819 - 2⁹ = 256307 is a prime.

It is a super-2 number, since 2×256819² = 131911997522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256813) 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, 7537 + ... + 7570.

It is an arithmetic number, because the mean of its divisors is an integer number (67986).

2²⁵⁶⁸¹⁹ is an apocalyptic number.

256819 is a deficient number, since it is larger than the sum of its proper divisors (15125).

256819 is a wasteful number, since it uses less digits than its factorization.

256819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15124.

The product of its digits is 4320, while the sum is 31.

The square root of 256819 is about 506.7731247807. The cubic root of 256819 is about 63.5636825738.

The spelling of 256819 in words is "two hundred fifty-six thousand, eight hundred nineteen".