28821664 has 24 divisors (see below), whose sum is σ = 60081588. Its totient is φ = 13562880.

The previous prime is 28821643. The next prime is 28821673. The reversal of 28821664 is 46612882.

It can be written as a sum of positive squares in 2 ways, for example, as 22165264 + 6656400 = 4708^2 + 2580^2 .

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, 25947 + ... + 27034.

Almost surely, 2^28821664 is an apocalyptic number.

It is an amenable number.

28821664 is an abundant number, since it is smaller than the sum of its proper divisors (31259924).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28821664 is a wasteful number, since it uses less digits than its factorization.

28821664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53008 (or 53000 counting only the distinct ones).

The product of its digits is 36864, while the sum is 37.

The square root of 28821664 is about 5368.5811905940. The cubic root of 28821664 is about 306.6006116919.

It can be divided in two parts, 288 and 21664, that added together give a cube (21952 = 28³).

The spelling of 28821664 in words is "twenty-eight million, eight hundred twenty-one thousand, six hundred sixty-four".