256659868517443 has 16 divisors (see below), whose sum is σ = 278358671642400. Its totient is φ = 235883200101120.

The previous prime is 256659868517407. The next prime is 256659868517449. The reversal of 256659868517443 is 344715868956652.

It is a happy number.

It is not a de Polignac number, because 256659868517443 - 2⁴⁵ = 221475496428611 is a prime.

It is a super-2 number, since 2×256659868517443² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256659868517449) 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, 1431796548 + ... + 1431975793.

It is an arithmetic number, because the mean of its divisors is an integer number (17397416977650).

Almost surely, 2^{256659868517443} is an apocalyptic number.

256659868517443 is a deficient number, since it is larger than the sum of its proper divisors (21698803124957).

256659868517443 is a wasteful number, since it uses less digits than its factorization.

256659868517443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2863772502.

The product of its digits is 10450944000, while the sum is 79.

The spelling of 256659868517443 in words is "two hundred fifty-six trillion, six hundred fifty-nine billion, eight hundred sixty-eight million, five hundred seventeen thousand, four hundred forty-three".