28781864 has 16 divisors (see below), whose sum is σ = 54146400. Its totient is φ = 14342832.

The previous prime is 28781849. The next prime is 28781873. The reversal of 28781864 is 46818782.

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 in 3 ways as a sum of consecutive naturals, for example, 3404 + ... + 8315.

It is an arithmetic number, because the mean of its divisors is an integer number (3384150).

Almost surely, 2^28781864 is an apocalyptic number.

It is an amenable number.

28781864 is a deficient number, since it is larger than the sum of its proper divisors (25364536).

28781864 is a wasteful number, since it uses less digits than its factorization.

28781864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12032 (or 12028 counting only the distinct ones).

The product of its digits is 172032, while the sum is 44.

The square root of 28781864 is about 5364.8731578668. The cubic root of 28781864 is about 306.4594178364.

The spelling of 28781864 in words is "twenty-eight million, seven hundred eighty-one thousand, eight hundred sixty-four".