320638921 has 8 divisors (see below), whose sum is σ = 350452224. Its totient is φ = 292042560.

The previous prime is 320638919. The next prime is 320638939. The reversal of 320638921 is 129836023.

It is a happy number.

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 320638921 - 2¹ = 320638919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320638961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 303685 + ... + 304738.

It is an arithmetic number, because the mean of its divisors is an integer number (43806528).

Almost surely, 2^320638921 is an apocalyptic number.

320638921 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

320638921 is a deficient number, since it is larger than the sum of its proper divisors (29813303).

320638921 is a wasteful number, since it uses less digits than its factorization.

320638921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608471.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 320638921 is about 17906.3932996011. The cubic root of 320638921 is about 684.4453008438.

The spelling of 320638921 in words is "three hundred twenty million, six hundred thirty-eight thousand, nine hundred twenty-one".