202121220221 has 16 divisors (see below), whose sum is σ = 220444886400. Its totient is φ = 184587076800.

The previous prime is 202121220209. The next prime is 202121220227. The reversal of 202121220221 is 122022121202.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 202121220221 - 2¹⁰ = 202121219197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 202121220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202121220227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57011 + ... + 638351.

It is an arithmetic number, because the mean of its divisors is an integer number (13777805400).

Almost surely, 2^202121220221 is an apocalyptic number.

It is an amenable number.

202121220221 is a deficient number, since it is larger than the sum of its proper divisors (18323666179).

202121220221 is a wasteful number, since it uses less digits than its factorization.

202121220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582020.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 202121220221 its reverse (122022121202), we get a palindrome (324143341423).

The spelling of 202121220221 in words is "two hundred two billion, one hundred twenty-one million, two hundred twenty thousand, two hundred twenty-one".