256801 has 2 divisors, whose sum is σ = 256802. Its totient is φ = 256800.

The previous prime is 256799. The next prime is 256813. The reversal of 256801 is 108652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180625 + 76176 = 425^2 + 276^2 .

It is a cyclic number.

It is not a de Polignac number, because 256801 - 2¹ = 256799 is a prime.

Together with 256799, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₂₂₅₈₅ and since 256801 and 22585 have the same sum of digits, it is a Honaker prime.

It is a nialpdrome in base 8.

It is not a weakly prime, because it can be changed into another prime (256831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128400 + 128401.

It is an arithmetic number, because the mean of its divisors is an integer number (128401).

2²⁵⁶⁸⁰¹ is an apocalyptic number.

256801 is the 321-st centered pentagonal number.

It is an amenable number.

256801 is a deficient number, since it is larger than the sum of its proper divisors (1).

256801 is an equidigital number, since it uses as much as digits as its factorization.

256801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 256801 is about 506.7553650431. The cubic root of 256801 is about 63.5621975162.

The spelling of 256801 in words is "two hundred fifty-six thousand, eight hundred one".