28668884 has 6 divisors (see below), whose sum is σ = 50170554. Its totient is φ = 14334440.

The previous prime is 28668859. The next prime is 28668931. The reversal of 28668884 is 48886682.

It can be written as a sum of positive squares in only one way, i.e., 19536400 + 9132484 = 4420^2 + 3022^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3583607 + ... + 3583614.

It is an arithmetic number, because the mean of its divisors is an integer number (8361759).

Almost surely, 2^28668884 is an apocalyptic number.

It is an amenable number.

28668884 is a deficient number, since it is larger than the sum of its proper divisors (21501670).

28668884 is a wasteful number, since it uses less digits than its factorization.

28668884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7167225 (or 7167223 counting only the distinct ones).

The product of its digits is 1179648, while the sum is 50.

The square root of 28668884 is about 5354.3331984478. Note that the first 3 decimals coincide. The cubic root of 28668884 is about 306.0579012423.

The spelling of 28668884 in words is "twenty-eight million, six hundred sixty-eight thousand, eight hundred eighty-four".