328291921 has 4 divisors (see below), whose sum is σ = 328345600. Its totient is φ = 328238244.

The previous prime is 328291889. The next prime is 328291927. The reversal of 328291921 is 129192823.

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 328291921 - 2⁵ = 328291889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (328291927) 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 3 ways as a sum of consecutive naturals, for example, 16281 + ... + 30358.

It is an arithmetic number, because the mean of its divisors is an integer number (82086400).

Almost surely, 2^328291921 is an apocalyptic number.

It is an amenable number.

328291921 is a deficient number, since it is larger than the sum of its proper divisors (53679).

328291921 is an equidigital number, since it uses as much as digits as its factorization.

328291921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53678.

The product of its digits is 15552, while the sum is 37.

The square root of 328291921 is about 18118.8278042483. The cubic root of 328291921 is about 689.8479823336.

The spelling of 328291921 in words is "three hundred twenty-eight million, two hundred ninety-one thousand, nine hundred twenty-one".