20320221 has 16 divisors (see below), whose sum is σ = 28172288. Its totient is φ = 13014000.

The previous prime is 20320211. The next prime is 20320241. The reversal of 20320221 is 12202302.

It is not a de Polignac number, because 20320221 - 2⁵ = 20320189 is a prime.

It is a super-2 number, since 2×20320221² = 825822762977682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20320197 and 20320206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20320211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13320 + ... + 14766.

It is an arithmetic number, because the mean of its divisors is an integer number (1760768).

Almost surely, 2^20320221 is an apocalyptic number.

It is an amenable number.

20320221 is a deficient number, since it is larger than the sum of its proper divisors (7852067).

20320221 is a wasteful number, since it uses less digits than its factorization.

20320221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 20320221 is about 4507.7955809908. The cubic root of 20320221 is about 272.8827872350.

Adding to 20320221 its reverse (12202302), we get a palindrome (32522523).

The spelling of 20320221 in words is "twenty million, three hundred twenty thousand, two hundred twenty-one".