256662811161 has 45 divisors (see below), whose sum is σ = 386783532399. Its totient is φ = 169616041200.

The previous prime is 256662811129. The next prime is 256662811177. The reversal of 256662811161 is 161118266652.

The square root of 256662811161 is 506619.

It is a perfect power (a square), and thus also a powerful number.

256662811161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 2828218761 + 253834592400 = 53181^2 + 503820^2 .

It is not a de Polignac number, because 256662811161 - 2⁵ = 256662811129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256662810161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 825282196 + ... + 825282506.

Almost surely, 2^256662811161 is an apocalyptic number.

256662811161 is the 506619-th square number.

256662811161 is the 253310-th centered octagonal number.

It is an amenable number.

256662811161 is a deficient number, since it is larger than the sum of its proper divisors (130120721238).

256662811161 is an frugal number, since it uses more digits than its factorization.

256662811161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996 (or 495 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The spelling of 256662811161 in words is "two hundred fifty-six billion, six hundred sixty-two million, eight hundred eleven thousand, one hundred sixty-one".