256705438 has 32 divisors (see below), whose sum is σ = 442755072. Its totient is φ = 110484000.

The previous prime is 256705433. The next prime is 256705453. The reversal of 256705438 is 834507652.

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

It is a self number, because there is not a number n which added to its sum of digits gives 256705438.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256705433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48595 + ... + 53617.

It is an arithmetic number, because the mean of its divisors is an integer number (13836096).

Almost surely, 2^256705438 is an apocalyptic number.

256705438 is a deficient number, since it is larger than the sum of its proper divisors (186049634).

256705438 is a wasteful number, since it uses less digits than its factorization.

256705438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5160.

The product of its (nonzero) digits is 201600, while the sum is 40.

The square root of 256705438 is about 16022.0297715364. The cubic root of 256705438 is about 635.5431218305.

The spelling of 256705438 in words is "two hundred fifty-six million, seven hundred five thousand, four hundred thirty-eight".