8781256161 has 12 divisors (see below), whose sum is σ = 12836857488. Its totient is φ = 5783638104.

The previous prime is 8781256157. The next prime is 8781256189. The reversal of 8781256161 is 1616521878.

8781256161 is a `hidden beast` number, since 8 + 7 + 8 + 1 + 25 + 616 + 1 = 666.

8781256161 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 8781256161 - 2² = 8781256157 is a prime.

It is a super-2 number, since 2×8781256161² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (8781257161) 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 11 ways as a sum of consecutive naturals, for example, 5876935 + ... + 5878428.

It is an arithmetic number, because the mean of its divisors is an integer number (1069738124).

Almost surely, 2^8781256161 is an apocalyptic number.

It is an amenable number.

8781256161 is a deficient number, since it is larger than the sum of its proper divisors (4055601327).

8781256161 is a wasteful number, since it uses less digits than its factorization.

8781256161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11755452 (or 11755449 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 8781256161 is about 93708.3569432311. The cubic root of 8781256161 is about 2063.0933637793.

The spelling of 8781256161 in words is "eight billion, seven hundred eighty-one million, two hundred fifty-six thousand, one hundred sixty-one".