20210020021 has 2 divisors, whose sum is σ = 20210020022. Its totient is φ = 20210020020.

The previous prime is 20210020003. The next prime is 20210020027. The reversal of 20210020021 is 12002001202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13136368996 + 7073651025 = 114614^2 + 84105^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210020021 - 2²¹ = 20207922869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20210020027) 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, 10105010010 + 10105010011.

It is an arithmetic number, because the mean of its divisors is an integer number (10105010011).

Almost surely, 2^20210020021 is an apocalyptic number.

It is an amenable number.

20210020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210020021 is an equidigital number, since it uses as much as digits as its factorization.

20210020021 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 10.

Adding to 20210020021 its reverse (12002001202), we get a palindrome (32212021223).

The spelling of 20210020021 in words is "twenty billion, two hundred ten million, twenty thousand, twenty-one".