202021221121 has 4 divisors (see below), whose sum is σ = 203809019652. Its totient is φ = 200233422592.

The previous prime is 202021221107. The next prime is 202021221139. The reversal of 202021221121 is 121122120202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2983890625 + 199037330496 = 54625^2 + 446136^2 .

It is a cyclic number.

It is not a de Polignac number, because 202021221121 - 2¹⁷ = 202021090049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202021221095 and 202021221104.

It is not an unprimeable number, because it can be changed into a prime (202021221151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 893899096 + ... + 893899321.

It is an arithmetic number, because the mean of its divisors is an integer number (50952254913).

Almost surely, 2^202021221121 is an apocalyptic number.

It is an amenable number.

202021221121 is a deficient number, since it is larger than the sum of its proper divisors (1787798531).

202021221121 is a wasteful number, since it uses less digits than its factorization.

202021221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1787798530.

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

Adding to 202021221121 its reverse (121122120202), we get a palindrome (323143341323).

The spelling of 202021221121 in words is "two hundred two billion, twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".