21221002112111 has 4 divisors (see below), whose sum is σ = 21223149344712. Its totient is φ = 21218854879512.

The previous prime is 21221002112027. The next prime is 21221002112119. The reversal of 21221002112111 is 11121120012212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221002112111 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 21221002112111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221002112119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1073601476 + ... + 1073621241.

It is an arithmetic number, because the mean of its divisors is an integer number (5305787336178).

Almost surely, 2^{21221002112111} is an apocalyptic number.

21221002112111 is a deficient number, since it is larger than the sum of its proper divisors (2147232601).

21221002112111 is an equidigital number, since it uses as much as digits as its factorization.

21221002112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147232600.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21221002112111 its reverse (11121120012212), we get a palindrome (32342122124323).

The spelling of 21221002112111 in words is "twenty-one trillion, two hundred twenty-one billion, two million, one hundred twelve thousand, one hundred eleven".