201221102081 has 2 divisors, whose sum is σ = 201221102082. Its totient is φ = 201221102080.

The previous prime is 201221102053. The next prime is 201221102171. The reversal of 201221102081 is 180201122102.

201221102081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128622649600 + 72598452481 = 358640^2 + 269441^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221102081 - 2²² = 201216907777 is a prime.

It is a super-2 number, since 2×201221102081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (201221102281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610551040 + 100610551041.

It is an arithmetic number, because the mean of its divisors is an integer number (100610551041).

Almost surely, 2^201221102081 is an apocalyptic number.

It is an amenable number.

201221102081 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221102081 is an equidigital number, since it uses as much as digits as its factorization.

201221102081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 201221102081 its reverse (180201122102), we get a palindrome (381422224183).

The spelling of 201221102081 in words is "two hundred one billion, two hundred twenty-one million, one hundred two thousand, eighty-one".