13328321 has 4 divisors (see below), whose sum is σ = 13653444. Its totient is φ = 13003200.

The previous prime is 13328309. The next prime is 13328353. The reversal of 13328321 is 12382331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12382331 = 13 ⋅952487.

It can be written as a sum of positive squares in 2 ways, for example, as 3940225 + 9388096 = 1985^2 + 3064^2 .

It is a cyclic number.

It is not a de Polignac number, because 13328321 - 2¹⁰ = 13327297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13328521) 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, 162500 + ... + 162581.

It is an arithmetic number, because the mean of its divisors is an integer number (3413361).

Almost surely, 2^13328321 is an apocalyptic number.

It is an amenable number.

13328321 is a deficient number, since it is larger than the sum of its proper divisors (325123).

13328321 is an equidigital number, since it uses as much as digits as its factorization.

13328321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325122.

The product of its digits is 864, while the sum is 23.

The square root of 13328321 is about 3650.7973101776. The cubic root of 13328321 is about 237.0965026837.

The spelling of 13328321 in words is "thirteen million, three hundred twenty-eight thousand, three hundred twenty-one".