21210111120121 has 8 divisors (see below), whose sum is σ = 26443774903104. Its totient is φ = 16527359314320.

The previous prime is 21210111120061. The next prime is 21210111120173. The reversal of 21210111120121 is 12102111101212.

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 21210111120121 - 2¹⁵ = 21210111087353 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210111120095 and 21210111120104.

It is not an unprimeable number, because it can be changed into a prime (21210111120521) 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 7 ways as a sum of consecutive naturals, for example, 137727994210 + ... + 137727994363.

It is an arithmetic number, because the mean of its divisors is an integer number (3305471862888).

Almost surely, 2^{21210111120121} is an apocalyptic number.

It is an amenable number.

21210111120121 is a deficient number, since it is larger than the sum of its proper divisors (5233663782983).

21210111120121 is a wasteful number, since it uses less digits than its factorization.

21210111120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275455988591.

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

Adding to 21210111120121 its reverse (12102111101212), we get a palindrome (33312222221333).

The spelling of 21210111120121 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, one hundred twenty thousand, one hundred twenty-one".