21111201202111 has 2 divisors, whose sum is σ = 21111201202112. Its totient is φ = 21111201202110.

The previous prime is 21111201202109. The next prime is 21111201202129. The reversal of 21111201202111 is 11120210211112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111201202111 - 2¹ = 21111201202109 is a prime.

Together with 21111201202109, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111201202171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555600601055 + 10555600601056.

It is an arithmetic number, because the mean of its divisors is an integer number (10555600601056).

Almost surely, 2^{21111201202111} is an apocalyptic number.

21111201202111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111201202111 is an equidigital number, since it uses as much as digits as its factorization.

21111201202111 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 16.

Adding to 21111201202111 its reverse (11120210211112), we get a palindrome (32231411413223).

Subtracting from 21111201202111 its reverse (11120210211112), we obtain a palindrome (9990990990999).

The spelling of 21111201202111 in words is "twenty-one trillion, one hundred eleven billion, two hundred one million, two hundred two thousand, one hundred eleven".