256684 has 6 divisors (see below), whose sum is σ = 449204. Its totient is φ = 128340.

The previous prime is 256661. The next prime is 256687. The reversal of 256684 is 486652.

It is not an unprimeable number, because it can be changed into a prime (256687) by changing a digit.

256684 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 32082 + ... + 32089.

2²⁵⁶⁶⁸⁴ is an apocalyptic number.

It is an amenable number.

256684 is a deficient number, since it is larger than the sum of its proper divisors (192520).

256684 is a wasteful number, since it uses less digits than its factorization.

256684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64175 (or 64173 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 256684 is about 506.6399115743. The cubic root of 256684 is about 63.5525429500.

The spelling of 256684 in words is "two hundred fifty-six thousand, six hundred eighty-four".