20211021020021 has 12 divisors (see below), whose sum is σ = 23121365014692. Its totient is φ = 17558896086528.

The previous prime is 20211021020011. The next prime is 20211021020041. The reversal of 20211021020021 is 12002012011202.

It can be written as a sum of positive squares in 6 ways, for example, as 372112200100 + 19838908819921 = 610010^2 + 4454089^2 .

It is not a de Polignac number, because 20211021020021 - 2⁶ = 20211021019957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20211021019978 and 20211021020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211021020011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2689778120 + ... + 2689785633.

It is an arithmetic number, because the mean of its divisors is an integer number (1926780417891).

Almost surely, 2^{20211021020021} is an apocalyptic number.

It is an amenable number.

20211021020021 is a deficient number, since it is larger than the sum of its proper divisors (2910343994671).

20211021020021 is a wasteful number, since it uses less digits than its factorization.

20211021020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5379563800 (or 5379563783 counting only the distinct ones).

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

Adding to 20211021020021 its reverse (12002012011202), we get a palindrome (32213033031223).

The spelling of 20211021020021 in words is "twenty trillion, two hundred eleven billion, twenty-one million, twenty thousand, twenty-one".