28208389 has 8 divisors (see below), whose sum is σ = 32583168. Its totient is φ = 24135360.

The previous prime is 28208381. The next prime is 28208429. The reversal of 28208389 is 98380282.

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 28208389 - 2³ = 28208381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28208381) 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, 75237 + ... + 75610.

It is an arithmetic number, because the mean of its divisors is an integer number (4072896).

Almost surely, 2^28208389 is an apocalyptic number.

It is an amenable number.

28208389 is a deficient number, since it is larger than the sum of its proper divisors (4374779).

28208389 is a wasteful number, since it uses less digits than its factorization.

28208389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150875.

The product of its (nonzero) digits is 55296, while the sum is 40.

The square root of 28208389 is about 5311.1570302524. The cubic root of 28208389 is about 304.4103595147.

The spelling of 28208389 in words is "twenty-eight million, two hundred eight thousand, three hundred eighty-nine".