2100211210021 has 2 divisors, whose sum is σ = 2100211210022. Its totient is φ = 2100211210020.

The previous prime is 2100211210007. The next prime is 2100211210037. The reversal of 2100211210021 is 1200121120012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1849124030625 + 251087179396 = 1359825^2 + 501086^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100211210021 - 2⁵ = 2100211209989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2100211209983 and 2100211210010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100211210051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050105605010 + 1050105605011.

It is an arithmetic number, because the mean of its divisors is an integer number (1050105605011).

Almost surely, 2^{2100211210021} is an apocalyptic number.

It is an amenable number.

2100211210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100211210021 is an equidigital number, since it uses as much as digits as its factorization.

2100211210021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2100211210021 its reverse (1200121120012), we get a palindrome (3300332330033).

Subtracting from 2100211210021 its reverse (1200121120012), we obtain a palindrome (900090090009).

The spelling of 2100211210021 in words is "two trillion, one hundred billion, two hundred eleven million, two hundred ten thousand, twenty-one".