256766321 has 12 divisors (see below), whose sum is σ = 298949040. Its totient is φ = 219892680.

The previous prime is 256766309. The next prime is 256766329. The reversal of 256766321 is 123667652.

It is not a de Polignac number, because 256766321 - 2¹⁴ = 256749937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256766329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 103190 + ... + 105648.

It is an arithmetic number, because the mean of its divisors is an integer number (24912420).

Almost surely, 2^256766321 is an apocalyptic number.

It is an amenable number.

256766321 is a deficient number, since it is larger than the sum of its proper divisors (42182719).

256766321 is a wasteful number, since it uses less digits than its factorization.

256766321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4604 (or 4597 counting only the distinct ones).

The product of its digits is 90720, while the sum is 38.

The square root of 256766321 is about 16023.9296366403. The cubic root of 256766321 is about 635.5933619210.

The spelling of 256766321 in words is "two hundred fifty-six million, seven hundred sixty-six thousand, three hundred twenty-one".