21002112110121 has 4 divisors (see below), whose sum is σ = 28002816146832. Its totient is φ = 14001408073412.

The previous prime is 21002112110101. The next prime is 21002112110167. The reversal of 21002112110121 is 12101121120012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21002112110121 - 2⁹ = 21002112109609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21002112110121.

It is not an unprimeable number, because it can be changed into a prime (21002112110101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3500352018351 + ... + 3500352018356.

It is an arithmetic number, because the mean of its divisors is an integer number (7000704036708).

Almost surely, 2^{21002112110121} is an apocalyptic number.

It is an amenable number.

21002112110121 is a deficient number, since it is larger than the sum of its proper divisors (7000704036711).

21002112110121 is an equidigital number, since it uses as much as digits as its factorization.

21002112110121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000704036710.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21002112110121 its reverse (12101121120012), we get a palindrome (33103233230133).

The spelling of 21002112110121 in words is "twenty-one trillion, two billion, one hundred twelve million, one hundred ten thousand, one hundred twenty-one".