21011201111111 has 2 divisors, whose sum is σ = 21011201111112. Its totient is φ = 21011201111110.

The previous prime is 21011201111107. The next prime is 21011201111113. The reversal of 21011201111111 is 11111110211012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21011201111111 - 2² = 21011201111107 is a prime.

Together with 21011201111113, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011201111113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505600555555 + 10505600555556.

It is an arithmetic number, because the mean of its divisors is an integer number (10505600555556).

Almost surely, 2^{21011201111111} is an apocalyptic number.

21011201111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011201111111 is an equidigital number, since it uses as much as digits as its factorization.

21011201111111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 14.

Adding to 21011201111111 its reverse (11111110211012), we get a palindrome (32122311322123).

Subtracting from 21011201111111 its reverse (11111110211012), we obtain a palindrome (9900090900099).

The spelling of 21011201111111 in words is "twenty-one trillion, eleven billion, two hundred one million, one hundred eleven thousand, one hundred eleven".