201121020021221 has 4 divisors (see below), whose sum is σ = 201121067501772. Its totient is φ = 201120972540672.

The previous prime is 201121020021217. The next prime is 201121020021227. The reversal of 201121020021221 is 122120020121102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 131990342577025 + 69130677444196 = 11488705^2 + 8314486^2 .

It is a cyclic number.

It is not a de Polignac number, because 201121020021221 - 2² = 201121020021217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 201121020021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201121020021227) 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, 16688210 + ... + 26090963.

It is an arithmetic number, because the mean of its divisors is an integer number (50280266875443).

Almost surely, 2^{201121020021221} is an apocalyptic number.

It is an amenable number.

201121020021221 is a deficient number, since it is larger than the sum of its proper divisors (47480551).

201121020021221 is an equidigital number, since it uses as much as digits as its factorization.

201121020021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47480550.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 201121020021221 its reverse (122120020121102), we get a palindrome (323241040142323).

The spelling of 201121020021221 in words is "two hundred one trillion, one hundred twenty-one billion, twenty million, twenty-one thousand, two hundred twenty-one".