202120222121 has 2 divisors, whose sum is σ = 202120222122. Its totient is φ = 202120222120.

The previous prime is 202120222039. The next prime is 202120222123. The reversal of 202120222121 is 121222021202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 155759672896 + 46360549225 = 394664^2 + 215315^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-202120222121 is a prime.

It is a Sophie Germain prime.

Together with 202120222123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 202120222121.

It is not a weakly prime, because it can be changed into another prime (202120222123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060111060 + 101060111061.

It is an arithmetic number, because the mean of its divisors is an integer number (101060111061).

Almost surely, 2^202120222121 is an apocalyptic number.

It is an amenable number.

202120222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

202120222121 is an equidigital number, since it uses as much as digits as its factorization.

202120222121 is an evil number, because the sum of its binary digits is even.

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

Adding to 202120222121 its reverse (121222021202), we get a palindrome (323342243323).

The spelling of 202120222121 in words is "two hundred two billion, one hundred twenty million, two hundred twenty-two thousand, one hundred twenty-one".