202020212221 has 8 divisors (see below), whose sum is σ = 204029753400. Its totient is φ = 200010854400.

The previous prime is 202020212203. The next prime is 202020212237. The reversal of 202020212221 is 122212020202.

It can be written as a sum of positive squares in 4 ways, for example, as 104979240025 + 97040972196 = 324005^2 + 311514^2 .

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 202020212221 - 2⁹ = 202020211709 is a prime.

It is a super-2 number, since 2×202020212221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202020212195 and 202020212204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202020212321) 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, 3605065 + ... + 3660673.

It is an arithmetic number, because the mean of its divisors is an integer number (25503719175).

Almost surely, 2^202020212221 is an apocalyptic number.

It is an amenable number.

202020212221 is a deficient number, since it is larger than the sum of its proper divisors (2009541179).

202020212221 is a wasteful number, since it uses less digits than its factorization.

202020212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91679.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 202020212221 its reverse (122212020202), we get a palindrome (324232232423).

It can be divided in two parts, 2020202 and 12221, that multiplied together give a palindrome (24688888642).

The spelling of 202020212221 in words is "two hundred two billion, twenty million, two hundred twelve thousand, two hundred twenty-one".