202121102021 has 2 divisors, whose sum is σ = 202121102022. Its totient is φ = 202121102020.

The previous prime is 202121101999. The next prime is 202121102059. The reversal of 202121102021 is 120201121202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 103870199521 + 98250902500 = 322289^2 + 313450^2 .

It is a cyclic number.

It is not a de Polignac number, because 202121102021 - 2¹⁰ = 202121100997 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202121101987 and 202121102005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202121102321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060551010 + 101060551011.

It is an arithmetic number, because the mean of its divisors is an integer number (101060551011).

Almost surely, 2^202121102021 is an apocalyptic number.

It is an amenable number.

202121102021 is a deficient number, since it is larger than the sum of its proper divisors (1).

202121102021 is an equidigital number, since it uses as much as digits as its factorization.

202121102021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 202121102021 its reverse (120201121202), we get a palindrome (322322223223).

The spelling of 202121102021 in words is "two hundred two billion, one hundred twenty-one million, one hundred two thousand, twenty-one".