28128784 has 20 divisors (see below), whose sum is σ = 54639360. Its totient is φ = 14028320.

The previous prime is 28128719. The next prime is 28128787. The reversal of 28128784 is 48782182.

It is not an unprimeable number, because it can be changed into a prime (28128787) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 4857 + ... + 8935.

It is an arithmetic number, because the mean of its divisors is an integer number (2731968).

Almost surely, 2^28128784 is an apocalyptic number.

It is an amenable number.

28128784 is a deficient number, since it is larger than the sum of its proper divisors (26510576).

28128784 is a wasteful number, since it uses less digits than its factorization.

28128784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4518 (or 4512 counting only the distinct ones).

The product of its digits is 57344, while the sum is 40.

The square root of 28128784 is about 5303.6576058415. The cubic root of 28128784 is about 304.1237377166.

The spelling of 28128784 in words is "twenty-eight million, one hundred twenty-eight thousand, seven hundred eighty-four".