28720544 has 12 divisors (see below), whose sum is σ = 56543634. Its totient is φ = 14360256.

The previous prime is 28720513. The next prime is 28720553. The reversal of 28720544 is 44502782.

It can be written as a sum of positive squares in only one way, i.e., 15904144 + 12816400 = 3988^2 + 3580^2 .

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 897517 = 28720544 / (2 + 8 + 7 + 2 + 0 + 5 + 4 + 4).

It is a self number, because there is not a number n which added to its sum of digits gives 28720544.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 448727 + ... + 448790.

Almost surely, 2^28720544 is an apocalyptic number.

It is an amenable number.

28720544 is a deficient number, since it is larger than the sum of its proper divisors (27823090).

28720544 is an equidigital number, since it uses as much as digits as its factorization.

28720544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897527 (or 897519 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 32.

The square root of 28720544 is about 5359.1551572986. The cubic root of 28720544 is about 306.2416249827.

The spelling of 28720544 in words is "twenty-eight million, seven hundred twenty thousand, five hundred forty-four".