256765 has 8 divisors (see below), whose sum is σ = 312120. Its totient is φ = 202752.

The previous prime is 256757. The next prime is 256771. The reversal of 256765 is 567652.

It can be written as a sum of positive squares in 4 ways, for example, as 60516 + 196249 = 246^2 + 443^2 .

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 256765 - 2³ = 256757 is a prime.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 157 + ... + 733.

It is an arithmetic number, because the mean of its divisors is an integer number (39015).

2²⁵⁶⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

256765 is a deficient number, since it is larger than the sum of its proper divisors (55355).

256765 is an equidigital number, since it uses as much as digits as its factorization.

256765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671.

The product of its digits is 12600, while the sum is 31.

The square root of 256765 is about 506.7198437006. The cubic root of 256765 is about 63.5592271928.

The spelling of 256765 in words is "two hundred fifty-six thousand, seven hundred sixty-five".