201221202221 has 16 divisors (see below), whose sum is σ = 221609409840. Its totient is φ = 181560437760.

The previous prime is 201221202211. The next prime is 201221202233. The reversal of 201221202221 is 122202122102.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 8210353321 + 193010848900 = 90611^2 + 439330^2 .

It is not a de Polignac number, because 201221202221 - 2²² = 201217007917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 201221202221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221202211) 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 15 ways as a sum of consecutive naturals, for example, 357500 + ... + 728181.

It is an arithmetic number, because the mean of its divisors is an integer number (13850588115).

Almost surely, 2^201221202221 is an apocalyptic number.

It is an amenable number.

201221202221 is a deficient number, since it is larger than the sum of its proper divisors (20388207619).

201221202221 is a wasteful number, since it uses less digits than its factorization.

201221202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086016.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 201221202221 its reverse (122202122102), we get a palindrome (323423324323).

The spelling of 201221202221 in words is "two hundred one billion, two hundred twenty-one million, two hundred two thousand, two hundred twenty-one".