202121102221 has 8 divisors (see below), whose sum is σ = 208123695864. Its totient is φ = 196169594880.

The previous prime is 202121102203. The next prime is 202121102233. The reversal of 202121102221 is 122201121202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 26129106025 + 175991996196 = 161645^2 + 419514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 202121102221 - 2¹⁵ = 202121069453 is a prime.

It is a super-2 number, since 2×202121102221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 202121102195 and 202121102204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121102291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12763546 + ... + 12779371.

It is an arithmetic number, because the mean of its divisors is an integer number (26015461983).

Almost surely, 2^202121102221 is an apocalyptic number.

It is an amenable number.

202121102221 is a deficient number, since it is larger than the sum of its proper divisors (6002593643).

202121102221 is a wasteful number, since it uses less digits than its factorization.

202121102221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25543151.

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

Adding to 202121102221 its reverse (122201121202), we get a palindrome (324322223423).

The spelling of 202121102221 in words is "two hundred two billion, one hundred twenty-one million, one hundred two thousand, two hundred twenty-one".