202120010021 has 2 divisors, whose sum is σ = 202120010022. Its totient is φ = 202120010020.

The previous prime is 202120010011. The next prime is 202120010023. The reversal of 202120010021 is 120010021202.

It is a happy number.

202120010021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181549279396 + 20570730625 = 426086^2 + 143425^2 .

It is a cyclic number.

It is not a de Polignac number, because 202120010021 - 2⁶ = 202120009957 is a prime.

Together with 202120010023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 202120009984 and 202120010011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202120010023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060005010 + 101060005011.

It is an arithmetic number, because the mean of its divisors is an integer number (101060005011).

Almost surely, 2^202120010021 is an apocalyptic number.

It is an amenable number.

202120010021 is a deficient number, since it is larger than the sum of its proper divisors (1).

202120010021 is an equidigital number, since it uses as much as digits as its factorization.

202120010021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 202120010021 its reverse (120010021202), we get a palindrome (322130031223).

It can be divided in two parts, 202 and 120010021, that multiplied together give a palindrome (24242024242).

The spelling of 202120010021 in words is "two hundred two billion, one hundred twenty million, ten thousand, twenty-one".