212210321 has 4 divisors (see below), whose sum is σ = 212453172. Its totient is φ = 211967472.

The previous prime is 212210309. The next prime is 212210329. The reversal of 212210321 is 123012212.

It is a happy number.

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 147889921 + 64320400 = 12161^2 + 8020^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212210321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212210296 and 212210305.

It is not an unprimeable number, because it can be changed into a prime (212210329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120110 + ... + 121863.

It is an arithmetic number, because the mean of its divisors is an integer number (53113293).

Almost surely, 2^212210321 is an apocalyptic number.

It is an amenable number.

212210321 is a deficient number, since it is larger than the sum of its proper divisors (242851).

212210321 is an equidigital number, since it uses as much as digits as its factorization.

212210321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242850.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 212210321 is about 14567.4404409285. The cubic root of 212210321 is about 596.4703142112.

Adding to 212210321 its reverse (123012212), we get a palindrome (335222533).

The spelling of 212210321 in words is "two hundred twelve million, two hundred ten thousand, three hundred twenty-one".