202121122012221 has 4 divisors (see below), whose sum is σ = 269494829349632. Its totient is φ = 134747414674812.

The previous prime is 202121122012217. The next prime is 202121122012247. The reversal of 202121122012221 is 122210221121202.

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 not a de Polignac number, because 202121122012221 - 2² = 202121122012217 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 (202121122062221) 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, 33686853668701 + ... + 33686853668706.

It is an arithmetic number, because the mean of its divisors is an integer number (67373707337408).

Almost surely, 2^{202121122012221} is an apocalyptic number.

It is an amenable number.

202121122012221 is a deficient number, since it is larger than the sum of its proper divisors (67373707337411).

202121122012221 is an equidigital number, since it uses as much as digits as its factorization.

202121122012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67373707337410.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 202121122012221 its reverse (122210221121202), we get a palindrome (324331343133423).

The spelling of 202121122012221 in words is "two hundred two trillion, one hundred twenty-one billion, one hundred twenty-two million, twelve thousand, two hundred twenty-one".