21112011101021 has 2 divisors, whose sum is σ = 21112011101022. Its totient is φ = 21112011101020.

The previous prime is 21112011101017. The next prime is 21112011101023. The reversal of 21112011101021 is 12010111021112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20271479692996 + 840531408025 = 4502386^2 + 916805^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112011101021 - 2² = 21112011101017 is a prime.

Together with 21112011101023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112011100987 and 21112011101005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112011101023) 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, 10556005550510 + 10556005550511.

It is an arithmetic number, because the mean of its divisors is an integer number (10556005550511).

Almost surely, 2^{21112011101021} is an apocalyptic number.

It is an amenable number.

21112011101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112011101021 is an equidigital number, since it uses as much as digits as its factorization.

21112011101021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21112011101021 its reverse (12010111021112), we get a palindrome (33122122122133).

The spelling of 21112011101021 in words is "twenty-one trillion, one hundred twelve billion, eleven million, one hundred one thousand, twenty-one".