28306289 has 8 divisors (see below), whose sum is σ = 30920832. Its totient is φ = 25698640.

The previous prime is 28306273. The next prime is 28306297. The reversal of 28306289 is 98260382.

It is a happy number.

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

It is not a de Polignac number, because 28306289 - 2⁴ = 28306273 is a prime.

It is a Duffinian number.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10967 + ... + 13299.

It is an arithmetic number, because the mean of its divisors is an integer number (3865104).

Almost surely, 2^28306289 is an apocalyptic number.

It is an amenable number.

28306289 is a deficient number, since it is larger than the sum of its proper divisors (2614543).

28306289 is a wasteful number, since it uses less digits than its factorization.

28306289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3447.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 28306289 is about 5320.3654949637. The cubic root of 28306289 is about 304.7621149665.

It can be divided in two parts, 2830 and 6289, that added together give a palindrome (9119).

The spelling of 28306289 in words is "twenty-eight million, three hundred six thousand, two hundred eighty-nine".