201212221 has 32 divisors (see below), whose sum is σ = 252626688. Its totient is φ = 156349440.

The previous prime is 201212161. The next prime is 201212273. The reversal of 201212221 is 122212102.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 201212221 - 2⁹ = 201211709 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 (201212021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 384466 + ... + 384988.

It is an arithmetic number, because the mean of its divisors is an integer number (7894584).

Almost surely, 2^201212221 is an apocalyptic number.

It is an amenable number.

201212221 is a deficient number, since it is larger than the sum of its proper divisors (51414467).

201212221 is a wasteful number, since it uses less digits than its factorization.

201212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661.

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

The square root of 201212221 is about 14184.9293618262. The cubic root of 201212221 is about 585.9826871145.

Adding to 201212221 its reverse (122212102), we get a palindrome (323424323).

The spelling of 201212221 in words is "two hundred one million, two hundred twelve thousand, two hundred twenty-one".