256428 has 36 divisors (see below), whose sum is σ = 687960. Its totient is φ = 80256.

The previous prime is 256423. The next prime is 256441. The reversal of 256428 is 824652.

It is a tau number, because it is divible by the number of its divisors (36).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256428.

It is not an unprimeable number, because it can be changed into a prime (256423) by changing a digit.

256428 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 403 + ... + 821.

It is an arithmetic number, because the mean of its divisors is an integer number (19110).

2²⁵⁶⁴²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343980).

256428 is an abundant number, since it is smaller than the sum of its proper divisors (431532).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256428 is a wasteful number, since it uses less digits than its factorization.

256428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446 (or 441 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 256428 is about 506.3872036298. The cubic root of 256428 is about 63.5314081919.

The spelling of 256428 in words is "two hundred fifty-six thousand, four hundred twenty-eight".