28153321 has 4 divisors (see below), whose sum is σ = 32175232. Its totient is φ = 24131412.

The previous prime is 28153313. The next prime is 28153331. The reversal of 28153321 is 12335182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28153321 - 2³ = 28153313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28153331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2010945 + ... + 2010958.

It is an arithmetic number, because the mean of its divisors is an integer number (8043808).

Almost surely, 2^28153321 is an apocalyptic number.

It is an amenable number.

28153321 is a deficient number, since it is larger than the sum of its proper divisors (4021911).

28153321 is an equidigital number, since it uses as much as digits as its factorization.

28153321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4021910.

The product of its digits is 1440, while the sum is 25.

The square root of 28153321 is about 5305.9703165397. The cubic root of 28153321 is about 304.2121420050.

The spelling of 28153321 in words is "twenty-eight million, one hundred fifty-three thousand, three hundred twenty-one".