21011002112021 has 2 divisors, whose sum is σ = 21011002112022. Its totient is φ = 21011002112020.

The previous prime is 21011002111991. The next prime is 21011002112077. The reversal of 21011002112021 is 12021120011012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20918640216100 + 92361895921 = 4573690^2 + 303911^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011002112021 - 2¹⁴ = 21011002095637 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21011002111987 and 21011002112005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011002112081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505501056010 + 10505501056011.

It is an arithmetic number, because the mean of its divisors is an integer number (10505501056011).

Almost surely, 2^{21011002112021} is an apocalyptic number.

It is an amenable number.

21011002112021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011002112021 is an equidigital number, since it uses as much as digits as its factorization.

21011002112021 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 14.

Adding to 21011002112021 its reverse (12021120011012), we get a palindrome (33032122123033).

The spelling of 21011002112021 in words is "twenty-one trillion, eleven billion, two million, one hundred twelve thousand, twenty-one".