28279289 has 4 divisors (see below), whose sum is σ = 28881024. Its totient is φ = 27677556.

The previous prime is 28279261. The next prime is 28279291. The reversal of 28279289 is 98297282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98297282 = 2 ⋅49148641.

It is a cyclic number.

It is not a de Polignac number, because 28279289 - 2¹⁶ = 28213753 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47), and also a Moran number because the ratio is a prime number: 601687 = 28279289 / (2 + 8 + 2 + 7 + 9 + 2 + 8 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28249289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 300797 + ... + 300890.

It is an arithmetic number, because the mean of its divisors is an integer number (7220256).

Almost surely, 2^28279289 is an apocalyptic number.

It is an amenable number.

28279289 is a deficient number, since it is larger than the sum of its proper divisors (601735).

28279289 is an equidigital number, since it uses as much as digits as its factorization.

28279289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601734.

The product of its digits is 290304, while the sum is 47.

The square root of 28279289 is about 5317.8274699354. The cubic root of 28279289 is about 304.6651848605.

The spelling of 28279289 in words is "twenty-eight million, two hundred seventy-nine thousand, two hundred eighty-nine".