28389321 has 12 divisors (see below), whose sum is σ = 41080000. Its totient is φ = 18892440.

The previous prime is 28389313. The next prime is 28389341. The reversal of 28389321 is 12398382.

It is a happy number.

It is not a de Polignac number, because 28389321 - 2³ = 28389313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28389341) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3180 + ... + 8178.

Almost surely, 2^28389321 is an apocalyptic number.

It is an amenable number.

28389321 is a deficient number, since it is larger than the sum of its proper divisors (12690679).

28389321 is a wasteful number, since it uses less digits than its factorization.

28389321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5636 (or 5633 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 28389321 is about 5328.1630042633. The cubic root of 28389321 is about 305.0598144804.

The spelling of 28389321 in words is "twenty-eight million, three hundred eighty-nine thousand, three hundred twenty-one".