21111022121111 has 8 divisors (see below), whose sum is σ = 22734987814560. Its totient is φ = 19487062272672.

The previous prime is 21111022121099. The next prime is 21111022121143. The reversal of 21111022121111 is 11112122011112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111022121111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21111022121111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111022321111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8612225 + ... + 10788533.

It is an arithmetic number, because the mean of its divisors is an integer number (2841873476820).

Almost surely, 2^{21111022121111} is an apocalyptic number.

21111022121111 is a deficient number, since it is larger than the sum of its proper divisors (1623965693449).

21111022121111 is a wasteful number, since it uses less digits than its factorization.

21111022121111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2922505.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 21111022121111 its reverse (11112122011112), we get a palindrome (32223144132223).

The spelling of 21111022121111 in words is "twenty-one trillion, one hundred eleven billion, twenty-two million, one hundred twenty-one thousand, one hundred eleven".