20021100200021 has 4 divisors (see below), whose sum is σ = 20026905103500. Its totient is φ = 20015295296544.

The previous prime is 20021100200011. The next prime is 20021100200027. The reversal of 20021100200021 is 12000200112002.

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 6607413699121 + 13413686500900 = 2570489^2 + 3662470^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021100200021 - 2¹⁸ = 20021099937877 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021100199975 and 20021100200011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021100200027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2902446566 + ... + 2902453463.

It is an arithmetic number, because the mean of its divisors is an integer number (5006726275875).

Almost surely, 2^{20021100200021} is an apocalyptic number.

It is an amenable number.

20021100200021 is a deficient number, since it is larger than the sum of its proper divisors (5804903479).

20021100200021 is an equidigital number, since it uses as much as digits as its factorization.

20021100200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5804903478.

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

Adding to 20021100200021 its reverse (12000200112002), we get a palindrome (32021300312023).

The spelling of 20021100200021 in words is "twenty trillion, twenty-one billion, one hundred million, two hundred thousand, twenty-one".