256822 has 4 divisors (see below), whose sum is σ = 385236. Its totient is φ = 128410.

The previous prime is 256813. The next prime is 256831. The reversal of 256822 is 228652.

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

It is an interprime number because it is at equal distance from previous prime (256813) and next prime (256831).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

256822 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64204 + ... + 64207.

It is an arithmetic number, because the mean of its divisors is an integer number (96309).

2²⁵⁶⁸²² is an apocalyptic number.

256822 is a deficient number, since it is larger than the sum of its proper divisors (128414).

256822 is a wasteful number, since it uses less digits than its factorization.

256822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128413.

The product of its digits is 1920, while the sum is 25.

The square root of 256822 is about 506.7760846765. The cubic root of 256822 is about 63.5639300767.

The spelling of 256822 in words is "two hundred fifty-six thousand, eight hundred twenty-two".