321221221 has 2 divisors, whose sum is σ = 321221222. Its totient is φ = 321221220.

The previous prime is 321221213. The next prime is 321221233. The reversal of 321221221 is 122122123.

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., 216384100 + 104837121 = 14710^2 + 10239^2 .

It is a cyclic number.

It is not a de Polignac number, because 321221221 - 2³ = 321221213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321221195 and 321221204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321221281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160610610 + 160610611.

It is an arithmetic number, because the mean of its divisors is an integer number (160610611).

Almost surely, 2^321221221 is an apocalyptic number.

It is an amenable number.

321221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

321221221 is an equidigital number, since it uses as much as digits as its factorization.

321221221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 16.

The square root of 321221221 is about 17922.6454799508. The cubic root of 321221221 is about 684.8593818661.

Adding to 321221221 its reverse (122122123), we get a palindrome (443343344).

It can be divided in two parts, 32122122 and 1, that added together give a palindrome (32122123).

The spelling of 321221221 in words is "three hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".