28165321 has 8 divisors (see below), whose sum is σ = 28485000. Its totient is φ = 27847680.

The previous prime is 28165309. The next prime is 28165327. The reversal of 28165321 is 12356182.

It can be written as a sum of positive squares in 4 ways, for example, as 455625 + 27709696 = 675^2 + 5264^2 .

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 28165321 - 2⁹ = 28164809 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28165321.

It is not an unprimeable number, because it can be changed into a prime (28165327) 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, 62505 + ... + 62953.

It is an arithmetic number, because the mean of its divisors is an integer number (3560625).

Almost surely, 2^28165321 is an apocalyptic number.

It is an amenable number.

28165321 is a deficient number, since it is larger than the sum of its proper divisors (319679).

28165321 is a wasteful number, since it uses less digits than its factorization.

28165321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1019.

The product of its digits is 2880, while the sum is 28.

The square root of 28165321 is about 5307.1009977199. The cubic root of 28165321 is about 304.2553580689.

The spelling of 28165321 in words is "twenty-eight million, one hundred sixty-five thousand, three hundred twenty-one".