21112221121 has 8 divisors (see below), whose sum is σ = 21801081600. Its totient is φ = 20423849520.

The previous prime is 21112221101. The next prime is 21112221131. The reversal of 21112221121 is 12112221112.

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

It is a cyclic number.

It is not a de Polignac number, because 21112221121 - 2⁷ = 21112220993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112221095 and 21112221104.

It is not an unprimeable number, because it can be changed into a prime (21112221101) 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, 33406 + ... + 208183.

It is an arithmetic number, because the mean of its divisors is an integer number (2725135200).

Almost surely, 2^21112221121 is an apocalyptic number.

It is an amenable number.

21112221121 is a deficient number, since it is larger than the sum of its proper divisors (688860479).

21112221121 is a wasteful number, since it uses less digits than its factorization.

21112221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244439.

The product of its digits is 32, while the sum is 16.

Adding to 21112221121 its reverse (12112221112), we get a palindrome (33224442233).

Subtracting from 21112221121 its reverse (12112221112), we obtain a palindrome (9000000009).

The spelling of 21112221121 in words is "twenty-one billion, one hundred twelve million, two hundred twenty-one thousand, one hundred twenty-one".