28305289 has 8 divisors (see below), whose sum is σ = 30418848. Its totient is φ = 26241600.

The previous prime is 28305227. The next prime is 28305313. The reversal of 28305289 is 98250382.

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

It is a cyclic number.

It is not a de Polignac number, because 28305289 - 2⁷ = 28305161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28309289) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11287 + ... + 13564.

It is an arithmetic number, because the mean of its divisors is an integer number (3802356).

Almost surely, 2^28305289 is an apocalyptic number.

It is an amenable number.

28305289 is a deficient number, since it is larger than the sum of its proper divisors (2113559).

28305289 is a wasteful number, since it uses less digits than its factorization.

28305289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24935.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 28305289 is about 5320.2715156278. The cubic root of 28305289 is about 304.7585260620.

The spelling of 28305289 in words is "twenty-eight million, three hundred five thousand, two hundred eighty-nine".