256369 has 2 divisors, whose sum is σ = 256370. Its totient is φ = 256368.

The previous prime is 256363. The next prime is 256391. The reversal of 256369 is 963652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 238144 + 18225 = 488^2 + 135^2 .

It is a cyclic number.

It is not a de Polignac number, because 256369 - 2⁵ = 256337 is a prime.

It is a super-2 number, since 2×256369² = 131450128322, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 256369.

It is not a weakly prime, because it can be changed into another prime (256363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128184 + 128185.

It is an arithmetic number, because the mean of its divisors is an integer number (128185).

2²⁵⁶³⁶⁹ is an apocalyptic number.

It is an amenable number.

256369 is a deficient number, since it is larger than the sum of its proper divisors (1).

256369 is an equidigital number, since it uses as much as digits as its factorization.

256369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 31.

The square root of 256369 is about 506.3289444620. The cubic root of 256369 is about 63.5265352963.

It can be divided in two parts, 256 and 369, that added together give a 4-th power (625 = 5⁴).

The spelling of 256369 in words is "two hundred fifty-six thousand, three hundred sixty-nine".