210212221 has 4 divisors (see below), whose sum is σ = 213775200. Its totient is φ = 206649244.

The previous prime is 210212201. The next prime is 210212227. The reversal of 210212221 is 122212012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210212221 - 2⁹ = 210211709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210212227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1781401 + ... + 1781518.

It is an arithmetic number, because the mean of its divisors is an integer number (53443800).

Almost surely, 2^210212221 is an apocalyptic number.

It is an amenable number.

210212221 is a deficient number, since it is larger than the sum of its proper divisors (3562979).

210212221 is an equidigital number, since it uses as much as digits as its factorization.

210212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3562978.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 210212221 is about 14498.6972173365. The cubic root of 210212221 is about 594.5923540663.

Adding to 210212221 its reverse (122212012), we get a palindrome (332424233).

The spelling of 210212221 in words is "two hundred ten million, two hundred twelve thousand, two hundred twenty-one".