320221021 has 4 divisors (see below), whose sum is σ = 323819100. Its totient is φ = 316622944.

The previous prime is 320221007. The next prime is 320221063. The reversal of 320221021 is 120122023.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55800900 + 264420121 = 7470^2 + 16261^2 .

It is a cyclic number.

It is not a de Polignac number, because 320221021 - 2⁷ = 320220893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 320220992 and 320221010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320221081) 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, 1798906 + ... + 1799083.

It is an arithmetic number, because the mean of its divisors is an integer number (80954775).

Almost surely, 2^320221021 is an apocalyptic number.

It is an amenable number.

320221021 is a deficient number, since it is larger than the sum of its proper divisors (3598079).

320221021 is an equidigital number, since it uses as much as digits as its factorization.

320221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3598078.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 320221021 is about 17894.7204783981. The cubic root of 320221021 is about 684.1478176764.

Adding to 320221021 its reverse (120122023), we get a palindrome (440343044).

The spelling of 320221021 in words is "three hundred twenty million, two hundred twenty-one thousand, twenty-one".