320989021 has 4 divisors (see below), whose sum is σ = 337883200. Its totient is φ = 304094844.

The previous prime is 320989007. The next prime is 320989033. The reversal of 320989021 is 120989023.

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 320989021 - 2²¹ = 318891869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320989051) 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, 8447061 + ... + 8447098.

It is an arithmetic number, because the mean of its divisors is an integer number (84470800).

Almost surely, 2^320989021 is an apocalyptic number.

It is an amenable number.

320989021 is a deficient number, since it is larger than the sum of its proper divisors (16894179).

320989021 is a wasteful number, since it uses less digits than its factorization.

320989021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16894178.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 320989021 is about 17916.1664705372. The cubic root of 320989021 is about 684.6943214952.

The spelling of 320989021 in words is "three hundred twenty million, nine hundred eighty-nine thousand, twenty-one".