8565661 has 4 divisors (see below), whose sum is σ = 9224572. Its totient is φ = 7906752.

The previous prime is 8565631. The next prime is 8565673. The reversal of 8565661 is 1665658.

8565661 = 2069² + 2070².

8565661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4284900 + 4280761 = 2070^2 + 2069^2 .

It is a cyclic number.

It is not a de Polignac number, because 8565661 - 2⁵ = 8565629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8565661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8565631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 329436 + ... + 329461.

It is an arithmetic number, because the mean of its divisors is an integer number (2306143).

Almost surely, 2^8565661 is an apocalyptic number.

8565661 is the 2070-th centered square number.

It is an amenable number.

8565661 is a deficient number, since it is larger than the sum of its proper divisors (658911).

8565661 is a wasteful number, since it uses less digits than its factorization.

8565661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658910.

The product of its digits is 43200, while the sum is 37.

The square root of 8565661 is about 2926.7150527511. The cubic root of 8565661 is about 204.6069088283.

The spelling of 8565661 in words is "eight million, five hundred sixty-five thousand, six hundred sixty-one".