28609864 has 8 divisors (see below), whose sum is σ = 53643510. Its totient is φ = 14304928.

The previous prime is 28609829. The next prime is 28609873. The reversal of 28609864 is 46890682.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 28536964 + 72900 = 5342^2 + 270^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 28609864.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1788109 + ... + 1788124.

Almost surely, 2^28609864 is an apocalyptic number.

It is an amenable number.

28609864 is a deficient number, since it is larger than the sum of its proper divisors (25033646).

28609864 is a wasteful number, since it uses less digits than its factorization.

28609864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3576239 (or 3576235 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 28609864 is about 5348.8189350547. The cubic root of 28609864 is about 305.8477320661.

The spelling of 28609864 in words is "twenty-eight million, six hundred nine thousand, eight hundred sixty-four".