21111100112221 has 8 divisors (see below), whose sum is σ = 24233257776960. Its totient is φ = 18015514002528.

The previous prime is 21111100112203. The next prime is 21111100112261. The reversal of 21111100112221 is 12221100111112.

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

It is not a de Polignac number, because 21111100112221 - 2⁵ = 21111100112189 is a prime.

It is a super-3 number, since 3×21111100112221³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111100112195 and 21111100112204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111100112261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6642887056 + ... + 6642890233.

It is an arithmetic number, because the mean of its divisors is an integer number (3029157222120).

Almost surely, 2^{21111100112221} is an apocalyptic number.

It is an amenable number.

21111100112221 is a deficient number, since it is larger than the sum of its proper divisors (3122157664739).

21111100112221 is a wasteful number, since it uses less digits than its factorization.

21111100112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13285777523.

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

Adding to 21111100112221 its reverse (12221100111112), we get a palindrome (33332200223333).

The spelling of 21111100112221 in words is "twenty-one trillion, one hundred eleven billion, one hundred million, one hundred twelve thousand, two hundred twenty-one".