202121132221 has 4 divisors (see below), whose sum is σ = 206821623712. Its totient is φ = 197420640732.

The previous prime is 202121132201. The next prime is 202121132231. The reversal of 202121132221 is 122231121202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 202121132221 - 2¹⁷ = 202121001149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121132201) 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, 2350245681 + ... + 2350245766.

It is an arithmetic number, because the mean of its divisors is an integer number (51705405928).

Almost surely, 2^202121132221 is an apocalyptic number.

It is an amenable number.

202121132221 is a deficient number, since it is larger than the sum of its proper divisors (4700491491).

202121132221 is an equidigital number, since it uses as much as digits as its factorization.

202121132221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4700491490.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 202121132221 its reverse (122231121202), we get a palindrome (324352253423).

The spelling of 202121132221 in words is "two hundred two billion, one hundred twenty-one million, one hundred thirty-two thousand, two hundred twenty-one".