202120121221 has 4 divisors (see below), whose sum is σ = 202121128492. Its totient is φ = 202119113952.

The previous prime is 202120121201. The next prime is 202120121233. The reversal of 202120121221 is 122121021202.

It is a happy number.

202120121221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 48995822500 + 153124298721 = 221350^2 + 391311^2 .

It is a cyclic number.

It is not a de Polignac number, because 202120121221 - 2³¹ = 199972637573 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202120121195 and 202120121204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202120121201) 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 in 3 ways as a sum of consecutive naturals, for example, 88680 + ... + 641953.

It is an arithmetic number, because the mean of its divisors is an integer number (50530282123).

Almost surely, 2^202120121221 is an apocalyptic number.

It is an amenable number.

202120121221 is a deficient number, since it is larger than the sum of its proper divisors (1007271).

202120121221 is an equidigital number, since it uses as much as digits as its factorization.

202120121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007270.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 202120121221 its reverse (122121021202), we get a palindrome (324241142423).

The spelling of 202120121221 in words is "two hundred two billion, one hundred twenty million, one hundred twenty-one thousand, two hundred twenty-one".