201210721221 has 64 divisors (see below), whose sum is σ = 297274798080. Its totient is φ = 120489431040.

The previous prime is 201210721207. The next prime is 201210721241. The reversal of 201210721221 is 122127012102.

It is not a de Polignac number, because 201210721221 - 2⁶ = 201210721157 is a prime.

It is a super-3 number, since 3×201210721221³ (a number of 35 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201210721241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78688875 + ... + 78691431.

It is an arithmetic number, because the mean of its divisors is an integer number (4644918720).

Almost surely, 2^201210721221 is an apocalyptic number.

It is an amenable number.

201210721221 is a deficient number, since it is larger than the sum of its proper divisors (96064076859).

201210721221 is a wasteful number, since it uses less digits than its factorization.

201210721221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3106.

The product of its (nonzero) digits is 224, while the sum is 21.

Adding to 201210721221 its reverse (122127012102), we get a palindrome (323337733323).

The spelling of 201210721221 in words is "two hundred one billion, two hundred ten million, seven hundred twenty-one thousand, two hundred twenty-one".