20002120210021 has 4 divisors (see below), whose sum is σ = 20004140432044. Its totient is φ = 20000099988000.

The previous prime is 20002120210003. The next prime is 20002120210073. The reversal of 20002120210021 is 12001202120002.

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 17074209089025 + 2927911120996 = 4132095^2 + 1711114^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002120210021 - 2¹¹ = 20002120207973 is a prime.

It is a super-2 number, since 2×20002120210021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20002120209983 and 20002120210010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20002120210001) 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 in 3 ways as a sum of consecutive naturals, for example, 1010096160 + ... + 1010115961.

It is an arithmetic number, because the mean of its divisors is an integer number (5001035108011).

Almost surely, 2^{20002120210021} is an apocalyptic number.

It is an amenable number.

20002120210021 is a deficient number, since it is larger than the sum of its proper divisors (2020222023).

20002120210021 is an equidigital number, since it uses as much as digits as its factorization.

20002120210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2020222022.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 20002120210021 its reverse (12001202120002), we get a palindrome (32003322330023).

The spelling of 20002120210021 in words is "twenty trillion, two billion, one hundred twenty million, two hundred ten thousand, twenty-one".