256667 has 8 divisors (see below), whose sum is σ = 270336. Its totient is φ = 243432.

The previous prime is 256661. The next prime is 256687. The reversal of 256667 is 766652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256667 - 2⁴ = 256651 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1958 + ... + 2084.

It is an arithmetic number, because the mean of its divisors is an integer number (33792).

2²⁵⁶⁶⁶⁷ is an apocalyptic number.

256667 is a deficient number, since it is larger than the sum of its proper divisors (13669).

256667 is a wasteful number, since it uses less digits than its factorization.

256667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217.

The product of its digits is 15120, while the sum is 32.

The square root of 256667 is about 506.6231340948. The cubic root of 256667 is about 63.5511399056.

The spelling of 256667 in words is "two hundred fifty-six thousand, six hundred sixty-seven".