8643664 has 20 divisors (see below), whose sum is σ = 17064756. Its totient is φ = 4239872.

The previous prime is 8643647. The next prime is 8643671. The reversal of 8643664 is 4663468.

It can be written as a sum of positive squares in 2 ways, for example, as 6210064 + 2433600 = 2492^2 + 1560^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4249 + ... + 5944.

Almost surely, 2^8643664 is an apocalyptic number.

It is an amenable number.

8643664 is a deficient number, since it is larger than the sum of its proper divisors (8421092).

8643664 is a wasteful number, since it uses less digits than its factorization.

8643664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10254 (or 10248 counting only the distinct ones).

The product of its digits is 82944, while the sum is 37.

The square root of 8643664 is about 2940.0108843336. The cubic root of 8643664 is about 205.2261157606.

It can be divided in two parts, 86436 and 64, that multiplied together give a square (5531904 = 2352²).

The spelling of 8643664 in words is "eight million, six hundred forty-three thousand, six hundred sixty-four".