20021100122021 has 2 divisors, whose sum is σ = 20021100122022. Its totient is φ = 20021100122020.

The previous prime is 20021100122017. The next prime is 20021100122143. The reversal of 20021100122021 is 12022100112002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19378880601025 + 642219520996 = 4402145^2 + 801386^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021100122021 - 2² = 20021100122017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20021100121987 and 20021100122005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021100128021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010550061010 + 10010550061011.

It is an arithmetic number, because the mean of its divisors is an integer number (10010550061011).

Almost surely, 2^{20021100122021} is an apocalyptic number.

It is an amenable number.

20021100122021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021100122021 is an equidigital number, since it uses as much as digits as its factorization.

20021100122021 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20021100122021 its reverse (12022100112002), we get a palindrome (32043200234023).

The spelling of 20021100122021 in words is "twenty trillion, twenty-one billion, one hundred million, one hundred twenty-two thousand, twenty-one".