28133788 has 12 divisors (see below), whose sum is σ = 49510440. Its totient is φ = 13987952.

The previous prime is 28133731. The next prime is 28133789. The reversal of 28133788 is 88733182.

It is a self number, because there is not a number n which added to its sum of digits gives 28133788.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28133789) 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 3 ways as a sum of consecutive naturals, for example, 18931 + ... + 20362.

It is an arithmetic number, because the mean of its divisors is an integer number (4125870).

Almost surely, 2^28133788 is an apocalyptic number.

It is an amenable number.

28133788 is a deficient number, since it is larger than the sum of its proper divisors (21376652).

28133788 is a wasteful number, since it uses less digits than its factorization.

28133788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39476 (or 39474 counting only the distinct ones).

The product of its digits is 64512, while the sum is 40.

The square root of 28133788 is about 5304.1293347731. The cubic root of 28133788 is about 304.1417707861.

The spelling of 28133788 in words is "twenty-eight million, one hundred thirty-three thousand, seven hundred eighty-eight".