256783 has 4 divisors (see below), whose sum is σ = 263088. Its totient is φ = 250480.

The previous prime is 256771. The next prime is 256799. The reversal of 256783 is 387652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256783 - 2¹⁷ = 125711 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3091 + ... + 3172.

It is an arithmetic number, because the mean of its divisors is an integer number (65772).

2²⁵⁶⁷⁸³ is an apocalyptic number.

256783 is a deficient number, since it is larger than the sum of its proper divisors (6305).

256783 is an equidigital number, since it uses as much as digits as its factorization.

256783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6304.

The product of its digits is 10080, while the sum is 31.

The square root of 256783 is about 506.7376046831. The cubic root of 256783 is about 63.5607123892.

The spelling of 256783 in words is "two hundred fifty-six thousand, seven hundred eighty-three".