28872389 has 8 divisors (see below), whose sum is σ = 35535360. Its totient is φ = 22844016.

The previous prime is 28872379. The next prime is 28872397. The reversal of 28872389 is 98327882.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-28872389 is a prime.

It is a super-2 number, since 2×28872389² = 1667229693134642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28872359) 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 7 ways as a sum of consecutive naturals, for example, 158549 + ... + 158730.

It is an arithmetic number, because the mean of its divisors is an integer number (4441920).

Almost surely, 2^28872389 is an apocalyptic number.

It is an amenable number.

28872389 is a deficient number, since it is larger than the sum of its proper divisors (6662971).

28872389 is a wasteful number, since it uses less digits than its factorization.

28872389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317299.

The product of its digits is 387072, while the sum is 47.

The square root of 28872389 is about 5373.3033601315. The cubic root of 28872389 is about 306.7803746313.

The spelling of 28872389 in words is "twenty-eight million, eight hundred seventy-two thousand, three hundred eighty-nine".