321221213 has 2 divisors, whose sum is σ = 321221214. Its totient is φ = 321221212.

The previous prime is 321221209. The next prime is 321221221. The reversal of 321221213 is 312122123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 280797049 + 40424164 = 16757^2 + 6358^2 .

It is a cyclic number.

It is not a de Polignac number, because 321221213 - 2² = 321221209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321221191 and 321221200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321221233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160610606 + 160610607.

It is an arithmetic number, because the mean of its divisors is an integer number (160610607).

Almost surely, 2^321221213 is an apocalyptic number.

It is an amenable number.

321221213 is a deficient number, since it is larger than the sum of its proper divisors (1).

321221213 is an equidigital number, since it uses as much as digits as its factorization.

321221213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 17.

The square root of 321221213 is about 17922.6452567694. The cubic root of 321221213 is about 684.8593761806.

Adding to 321221213 its reverse (312122123), we get a palindrome (633343336).

The spelling of 321221213 in words is "three hundred twenty-one million, two hundred twenty-one thousand, two hundred thirteen".