8564661 has 18 divisors (see below), whose sum is σ = 14391702. Its totient is φ = 4893840.

The previous prime is 8564653. The next prime is 8564681. The reversal of 8564661 is 1664658.

8564661 is a `hidden beast` number, since 8 + 5 + 646 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8520561 + 44100 = 2919^2 + 210^2 .

It is not a de Polignac number, because 8564661 - 2³ = 8564653 is a prime.

8564661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8564681) 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 17 ways as a sum of consecutive naturals, for example, 9270 + ... + 10151.

It is an arithmetic number, because the mean of its divisors is an integer number (799539).

Almost surely, 2^8564661 is an apocalyptic number.

It is an amenable number.

8564661 is a deficient number, since it is larger than the sum of its proper divisors (5827041).

8564661 is a wasteful number, since it uses less digits than its factorization.

8564661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19441 (or 19431 counting only the distinct ones).

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

The square root of 8564661 is about 2926.5442077645. The cubic root of 8564661 is about 204.5989462254.

It can be divided in two parts, 85 and 64661, that added together give a palindrome (64746).

The spelling of 8564661 in words is "eight million, five hundred sixty-four thousand, six hundred sixty-one".