256716321 has 16 divisors (see below), whose sum is σ = 350809536. Its totient is φ = 166896576.

The previous prime is 256716319. The next prime is 256716331. The reversal of 256716321 is 123617652.

256716321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256716321 - 2¹ = 256716319 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256716311) 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, 108871 + ... + 111203.

It is an arithmetic number, because the mean of its divisors is an integer number (21925596).

Almost surely, 2^256716321 is an apocalyptic number.

It is an amenable number.

256716321 is a deficient number, since it is larger than the sum of its proper divisors (94093215).

256716321 is a wasteful number, since it uses less digits than its factorization.

256716321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3232.

The product of its digits is 15120, while the sum is 33.

The square root of 256716321 is about 16022.3693940690. The cubic root of 256716321 is about 635.5521029649.

The spelling of 256716321 in words is "two hundred fifty-six million, seven hundred sixteen thousand, three hundred twenty-one".