28704820 has 24 divisors (see below), whose sum is σ = 63453600. Its totient is φ = 10877472.

The previous prime is 28704811. The next prime is 28704883. The reversal of 28704820 is 2840782.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37390 + ... + 38149.

It is an arithmetic number, because the mean of its divisors is an integer number (2643900).

Almost surely, 2^28704820 is an apocalyptic number.

28704820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28704820 is an abundant number, since it is smaller than the sum of its proper divisors (34748780).

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

28704820 is a wasteful number, since it uses less digits than its factorization.

28704820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75567 (or 75565 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 28704820 is about 5357.6879341746. The cubic root of 28704820 is about 306.1857274534.

The spelling of 28704820 in words is "twenty-eight million, seven hundred four thousand, eight hundred twenty".