256561452321 has 8 divisors (see below), whose sum is σ = 342875631744. Its totient is φ = 170644120560.

The previous prime is 256561452253. The next prime is 256561452341. The reversal of 256561452321 is 123254165652.

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

It is not a de Polignac number, because 256561452321 - 2¹¹ = 256561450273 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (256561452341) 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 7 ways as a sum of consecutive naturals, for example, 99210406 + ... + 99212991.

It is an arithmetic number, because the mean of its divisors is an integer number (42859453968).

Almost surely, 2^256561452321 is an apocalyptic number.

It is an amenable number.

256561452321 is a deficient number, since it is larger than the sum of its proper divisors (86314179423).

256561452321 is a wasteful number, since it uses less digits than its factorization.

256561452321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198423831.

The product of its digits is 432000, while the sum is 42.

The spelling of 256561452321 in words is "two hundred fifty-six billion, five hundred sixty-one million, four hundred fifty-two thousand, three hundred twenty-one".