21102102211111 has 4 divisors (see below), whose sum is σ = 21102177160512. Its totient is φ = 21102027261712.

The previous prime is 21102102211031. The next prime is 21102102211163. The reversal of 21102102211111 is 11111220120112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21102102211111 - 2¹⁹ = 21102101686823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102502211111) 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 in 3 ways as a sum of consecutive naturals, for example, 37050775 + ... + 37616008.

It is an arithmetic number, because the mean of its divisors is an integer number (5275544290128).

Almost surely, 2^{21102102211111} is an apocalyptic number.

21102102211111 is a deficient number, since it is larger than the sum of its proper divisors (74949401).

21102102211111 is an equidigital number, since it uses as much as digits as its factorization.

21102102211111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74949400.

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

Adding to 21102102211111 its reverse (11111220120112), we get a palindrome (32213322331223).

The spelling of 21102102211111 in words is "twenty-one trillion, one hundred two billion, one hundred two million, two hundred eleven thousand, one hundred eleven".