202131221 has 4 divisors (see below), whose sum is σ = 202207500. Its totient is φ = 202054944.

The previous prime is 202131197. The next prime is 202131229. The reversal of 202131221 is 122131202.

It is a happy number.

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 78676900 + 123454321 = 8870^2 + 11111^2 .

It is a cyclic number.

It is not a de Polignac number, because 202131221 - 2⁶ = 202131157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202131196 and 202131205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202131229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34016 + ... + 39513.

It is an arithmetic number, because the mean of its divisors is an integer number (50551875).

Almost surely, 2^202131221 is an apocalyptic number.

It is an amenable number.

202131221 is a deficient number, since it is larger than the sum of its proper divisors (76279).

202131221 is an equidigital number, since it uses as much as digits as its factorization.

202131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76278.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 202131221 is about 14217.2859927625. The cubic root of 202131221 is about 586.8734552461.

Adding to 202131221 its reverse (122131202), we get a palindrome (324262423).

The spelling of 202131221 in words is "two hundred two million, one hundred thirty-one thousand, two hundred twenty-one".