8646561 has 32 divisors (see below), whose sum is σ = 15974400. Its totient is φ = 4490640.

The previous prime is 8646559. The next prime is 8646571. The reversal of 8646561 is 1656468.

8646561 is a `hidden beast` number, since 8 + 646 + 5 + 6 + 1 = 666.

8646561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

8646561 is a nontrivial binomial coefficient, being equal to C(4159, 2).

It is not a de Polignac number, because 8646561 - 2¹ = 8646559 is a prime.

It is a Curzon number.

8646561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8646511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1 + ... + 4158.

It is an arithmetic number, because the mean of its divisors is an integer number (499200).

Almost surely, 2^8646561 is an apocalyptic number.

8646561 is the 4158-th triangular number.

It is an amenable number.

8646561 is a deficient number, since it is larger than the sum of its proper divisors (7327839).

8646561 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (8646560) it forms an eRAP, since the sums of their prime factors are consecutive (4185 and 4186).

8646561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4186 (or 4180 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 8646561 is about 2940.5035283094. The cubic root of 8646561 is about 205.2490409787.

The spelling of 8646561 in words is "eight million, six hundred forty-six thousand, five hundred sixty-one".