21220020122111 has 4 divisors (see below), whose sum is σ = 21251088966312. Its totient is φ = 21188951277912.

The previous prime is 21220020122047. The next prime is 21220020122129. The reversal of 21220020122111 is 11122102002212.

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 21220020122111 - 2⁶ = 21220020122047 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 21220020122111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220020122011) 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, 15534421076 + ... + 15534422441.

It is an arithmetic number, because the mean of its divisors is an integer number (5312772241578).

Almost surely, 2^{21220020122111} is an apocalyptic number.

21220020122111 is a deficient number, since it is larger than the sum of its proper divisors (31068844201).

21220020122111 is an equidigital number, since it uses as much as digits as its factorization.

21220020122111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31068844200.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21220020122111 its reverse (11122102002212), we get a palindrome (32342122124323).

The spelling of 21220020122111 in words is "twenty-one trillion, two hundred twenty billion, twenty million, one hundred twenty-two thousand, one hundred eleven".