28139368 has 8 divisors (see below), whose sum is σ = 52761330. Its totient is φ = 14069680.

The previous prime is 28139357. The next prime is 28139381. The reversal of 28139368 is 86393182.

It can be written as a sum of positive squares in only one way, i.e., 27646564 + 492804 = 5258^2 + 702^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 28139368.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1758703 + ... + 1758718.

Almost surely, 2^28139368 is an apocalyptic number.

It is an amenable number.

28139368 is a deficient number, since it is larger than the sum of its proper divisors (24621962).

28139368 is a wasteful number, since it uses less digits than its factorization.

28139368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3517427 (or 3517423 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 28139368 is about 5304.6553139672. The cubic root of 28139368 is about 304.1618770831.

The spelling of 28139368 in words is "twenty-eight million, one hundred thirty-nine thousand, three hundred sixty-eight".