202121131221 has 48 divisors (see below), whose sum is σ = 310415362560. Its totient is φ = 129847320000.

The previous prime is 202121131211. The next prime is 202121131237. The reversal of 202121131221 is 122131121202.

202121131221 is a `hidden beast` number, since 202 + 1 + 211 + 31 + 221 = 666.

It is not a de Polignac number, because 202121131221 - 2³⁰ = 201047389397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202121131194 and 202121131203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121131211) 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 47 ways as a sum of consecutive naturals, for example, 52729921 + ... + 52733753.

It is an arithmetic number, because the mean of its divisors is an integer number (6466986720).

Almost surely, 2^202121131221 is an apocalyptic number.

It is an amenable number.

202121131221 is a deficient number, since it is larger than the sum of its proper divisors (108294231339).

202121131221 is an equidigital number, since it uses as much as digits as its factorization.

202121131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4375 (or 4118 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 202121131221 its reverse (122131121202), we get a palindrome (324252252423).

The spelling of 202121131221 in words is "two hundred two billion, one hundred twenty-one million, one hundred thirty-one thousand, two hundred twenty-one".