21020122111 has 4 divisors (see below), whose sum is σ = 21023388000. Its totient is φ = 21016856224.

The previous prime is 21020122093. The next prime is 21020122129. The reversal of 21020122111 is 11122102012.

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

It is an interprime number because it is at equal distance from previous prime (21020122093) and next prime (21020122129).

It is a cyclic number.

It is not a de Polignac number, because 21020122111 - 2¹¹ = 21020120063 is a prime.

It is a super-2 number, since 2×21020122111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020122091 and 21020122100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020122811) 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, 1623271 + ... + 1636168.

It is an arithmetic number, because the mean of its divisors is an integer number (5255847000).

Almost surely, 2^21020122111 is an apocalyptic number.

21020122111 is a deficient number, since it is larger than the sum of its proper divisors (3265889).

21020122111 is an equidigital number, since it uses as much as digits as its factorization.

21020122111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3265888.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21020122111 its reverse (11122102012), we get a palindrome (32142224123).

The spelling of 21020122111 in words is "twenty-one billion, twenty million, one hundred twenty-two thousand, one hundred eleven".