256390 has 8 divisors (see below), whose sum is σ = 461520. Its totient is φ = 102552.

The previous prime is 256369. The next prime is 256391. The reversal of 256390 is 93652.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256391) 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, 12810 + ... + 12829.

It is an arithmetic number, because the mean of its divisors is an integer number (57690).

2²⁵⁶³⁹⁰ is an apocalyptic number.

256390 is a deficient number, since it is larger than the sum of its proper divisors (205130).

256390 is a wasteful number, since it uses less digits than its factorization.

256390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25646.

The product of its (nonzero) digits is 1620, while the sum is 25.

The square root of 256390 is about 506.3496815443. The cubic root of 256390 is about 63.5282698025.

It can be divided in two parts, 256 and 390, that added together give a palindrome (646).

The spelling of 256390 in words is "two hundred fifty-six thousand, three hundred ninety".