28220684 has 12 divisors (see below), whose sum is σ = 49455504. Its totient is φ = 14090544.

The previous prime is 28220671. The next prime is 28220711. The reversal of 28220684 is 48602282.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 28220684.

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, 1472 + ... + 7655.

It is an arithmetic number, because the mean of its divisors is an integer number (4121292).

Almost surely, 2^28220684 is an apocalyptic number.

It is an amenable number.

28220684 is a deficient number, since it is larger than the sum of its proper divisors (21234820).

28220684 is a wasteful number, since it uses less digits than its factorization.

28220684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9904 (or 9902 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 32.

The square root of 28220684 is about 5312.3143732275. The cubic root of 28220684 is about 304.4545801864.

The spelling of 28220684 in words is "twenty-eight million, two hundred twenty thousand, six hundred eighty-four".