28784778 has 32 divisors (see below), whose sum is σ = 63191232. Its totient is φ = 8668800.

The previous prime is 28784773. The next prime is 28784801. The reversal of 28784778 is 87748782.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28784778.

It is not an unprimeable number, because it can be changed into a prime (28784773) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 10158 + ... + 12678.

It is an arithmetic number, because the mean of its divisors is an integer number (1974726).

Almost surely, 2^28784778 is an apocalyptic number.

28784778 is an abundant number, since it is smaller than the sum of its proper divisors (34406454).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28784778 is a wasteful number, since it uses less digits than its factorization.

28784778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2710.

The product of its digits is 1404928, while the sum is 51.

The square root of 28784778 is about 5365.1447324373. The cubic root of 28784778 is about 306.4697599116.

The spelling of 28784778 in words is "twenty-eight million, seven hundred eighty-four thousand, seven hundred seventy-eight".