256769 has 4 divisors (see below), whose sum is σ = 257796. Its totient is φ = 255744.

The previous prime is 256757. The next prime is 256771. The reversal of 256769 is 967652.

256769 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 87025 + 169744 = 295^2 + 412^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256769 is a prime.

It is a super-2 number, since 2×256769² = 131860638722, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2 + 5⁷ + 7⁶ + 6⁵ + 6⁶ + 9⁴ .

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256799) 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, 137 + ... + 729.

It is an arithmetic number, because the mean of its divisors is an integer number (64449).

2²⁵⁶⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

256769 is a deficient number, since it is larger than the sum of its proper divisors (1027).

256769 is an equidigital number, since it uses as much as digits as its factorization.

256769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1026.

The product of its digits is 22680, while the sum is 35.

The square root of 256769 is about 506.7237906394. The cubic root of 256769 is about 63.5595572425.

The spelling of 256769 in words is "two hundred fifty-six thousand, seven hundred sixty-nine".