21112320121 has 8 divisors (see below), whose sum is σ = 21333914784. Its totient is φ = 20891175360.

The previous prime is 21112320113. The next prime is 21112320133. The reversal of 21112320121 is 12102321112.

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 21112320121 - 2³ = 21112320113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112320095 and 21112320104.

It is not an unprimeable number, because it can be changed into a prime (21112320191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17715 + ... + 206248.

It is an arithmetic number, because the mean of its divisors is an integer number (2666739348).

Almost surely, 2^21112320121 is an apocalyptic number.

It is an amenable number.

21112320121 is a deficient number, since it is larger than the sum of its proper divisors (221594663).

21112320121 is a wasteful number, since it uses less digits than its factorization.

21112320121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224951.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21112320121 its reverse (12102321112), we get a palindrome (33214641233).

Subtracting from 21112320121 its reverse (12102321112), we obtain a palindrome (9009999009).

It can be divided in two parts, 2111 and 2320121, that added together give a palindrome (2322232).

The spelling of 21112320121 in words is "twenty-one billion, one hundred twelve million, three hundred twenty thousand, one hundred twenty-one".