321320221 has 2 divisors, whose sum is σ = 321320222. Its totient is φ = 321320220.

The previous prime is 321320183. The next prime is 321320269. The reversal of 321320221 is 122023123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 301196025 + 20124196 = 17355^2 + 4486^2 .

It is a cyclic number.

It is not a de Polignac number, because 321320221 - 2⁹ = 321319709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321320195 and 321320204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321320521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160660110 + 160660111.

It is an arithmetic number, because the mean of its divisors is an integer number (160660111).

Almost surely, 2^321320221 is an apocalyptic number.

It is an amenable number.

321320221 is a deficient number, since it is larger than the sum of its proper divisors (1).

321320221 is an equidigital number, since it uses as much as digits as its factorization.

321320221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 321320221 is about 17925.4071362410. The cubic root of 321320221 is about 684.9297322561.

Adding to 321320221 its reverse (122023123), we get a palindrome (443343344).

The spelling of 321320221 in words is "three hundred twenty-one million, three hundred twenty thousand, two hundred twenty-one".