20320321 has 8 divisors (see below), whose sum is σ = 24589440. Its totient is φ = 16392768.

The previous prime is 20320303. The next prime is 20320343. The reversal of 20320321 is 12302302.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20320321 - 2⁹ = 20319809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20320361) 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, 85261 + ... + 85498.

It is an arithmetic number, because the mean of its divisors is an integer number (3073680).

Almost surely, 2^20320321 is an apocalyptic number.

It is an amenable number.

20320321 is a deficient number, since it is larger than the sum of its proper divisors (4269119).

20320321 is a wasteful number, since it uses less digits than its factorization.

20320321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170783.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 20320321 is about 4507.8066728732. The cubic root of 20320321 is about 272.8832348717.

Adding to 20320321 its reverse (12302302), we get a palindrome (32622623).

The spelling of 20320321 in words is "twenty million, three hundred twenty thousand, three hundred twenty-one".