21120111021111 has 8 divisors (see below), whose sum is σ = 28220448132864. Its totient is φ = 14049923961720.

The previous prime is 21120111021101. The next prime is 21120111021203. The reversal of 21120111021111 is 11112011102112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21120111021111 - 2¹⁵ = 21120110988343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120111021101) 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 7 ways as a sum of consecutive naturals, for example, 7537511455 + ... + 7537514256.

It is an arithmetic number, because the mean of its divisors is an integer number (3527556016608).

Almost surely, 2^{21120111021111} is an apocalyptic number.

21120111021111 is a deficient number, since it is larger than the sum of its proper divisors (7100337111753).

21120111021111 is a wasteful number, since it uses less digits than its factorization.

21120111021111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15075026181.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 21120111021111 its reverse (11112011102112), we get a palindrome (32232122123223).

It can be divided in two parts, 2112011102111 and 1, that added together give a palindrome (2112011102112).

The spelling of 21120111021111 in words is "twenty-one trillion, one hundred twenty billion, one hundred eleven million, twenty-one thousand, one hundred eleven".