256390554673 has 4 divisors (see below), whose sum is σ = 279698786928. Its totient is φ = 233082322420.

The previous prime is 256390554671. The next prime is 256390554691. The reversal of 256390554673 is 376455093652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256390554673 - 2¹ = 256390554671 is a prime.

It is a super-2 number, since 2×256390554673² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (256390554671) 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 3 ways as a sum of consecutive naturals, for example, 11654116111 + ... + 11654116132.

It is an arithmetic number, because the mean of its divisors is an integer number (69924696732).

Almost surely, 2^256390554673 is an apocalyptic number.

It is an amenable number.

256390554673 is a deficient number, since it is larger than the sum of its proper divisors (23308232255).

256390554673 is a wasteful number, since it uses less digits than its factorization.

256390554673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23308232254.

The product of its (nonzero) digits is 20412000, while the sum is 55.

The spelling of 256390554673 in words is "two hundred fifty-six billion, three hundred ninety million, five hundred fifty-four thousand, six hundred seventy-three".