28664644 has 18 divisors (see below), whose sum is σ = 51958634. Its totient is φ = 13836480.

The previous prime is 28664641. The next prime is 28664651. The reversal of 28664644 is 44646682.

It can be written as a sum of positive squares in 3 ways, for example, as 4536900 + 24127744 = 2130^2 + 4912^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28664597 and 28664606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28664641) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 897 + ... + 7624.

Almost surely, 2^28664644 is an apocalyptic number.

It is an amenable number.

28664644 is a deficient number, since it is larger than the sum of its proper divisors (23293990).

28664644 is a wasteful number, since it uses less digits than its factorization.

28664644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8583 (or 8552 counting only the distinct ones).

The product of its digits is 221184, while the sum is 40.

The square root of 28664644 is about 5353.9372428149. The cubic root of 28664644 is about 306.0428122991.

The spelling of 28664644 in words is "twenty-eight million, six hundred sixty-four thousand, six hundred forty-four".