28128259 has 4 divisors (see below), whose sum is σ = 28589440. Its totient is φ = 27667080.

The previous prime is 28128229. The next prime is 28128271. The reversal of 28128259 is 95282182.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28128259 - 2⁹ = 28127747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28128229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230499 + ... + 230620.

It is an arithmetic number, because the mean of its divisors is an integer number (7147360).

Almost surely, 2^28128259 is an apocalyptic number.

28128259 is a deficient number, since it is larger than the sum of its proper divisors (461181).

28128259 is an equidigital number, since it uses as much as digits as its factorization.

28128259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461180.

The product of its digits is 23040, while the sum is 37.

The square root of 28128259 is about 5303.6081114653. The cubic root of 28128259 is about 304.1218456339.

The spelling of 28128259 in words is "twenty-eight million, one hundred twenty-eight thousand, two hundred fifty-nine".