320031221 has 2 divisors, whose sum is σ = 320031222. Its totient is φ = 320031220.

The previous prime is 320031209. The next prime is 320031247. The reversal of 320031221 is 122130023.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 175695025 + 144336196 = 13255^2 + 12014^2 .

It is a cyclic number.

It is not a de Polignac number, because 320031221 - 2¹⁴ = 320014837 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 320031196 and 320031205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320031251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160015610 + 160015611.

It is an arithmetic number, because the mean of its divisors is an integer number (160015611).

Almost surely, 2^320031221 is an apocalyptic number.

It is an amenable number.

320031221 is a deficient number, since it is larger than the sum of its proper divisors (1).

320031221 is an equidigital number, since it uses as much as digits as its factorization.

320031221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 320031221 is about 17889.4164521932. The cubic root of 320031221 is about 684.0126225969.

Adding to 320031221 its reverse (122130023), we get a palindrome (442161244).

The spelling of 320031221 in words is "three hundred twenty million, thirty-one thousand, two hundred twenty-one".