21201012210121 has 4 divisors (see below), whose sum is σ = 21208034741200. Its totient is φ = 21193989679044.

The previous prime is 21201012210089. The next prime is 21201012210127. The reversal of 21201012210121 is 12101221010212.

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 21201012210121 - 2⁵ = 21201012210089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201012210095 and 21201012210104.

It is not an unprimeable number, because it can be changed into a prime (21201012210127) 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 3 ways as a sum of consecutive naturals, for example, 3511261011 + ... + 3511267048.

It is an arithmetic number, because the mean of its divisors is an integer number (5302008685300).

Almost surely, 2^{21201012210121} is an apocalyptic number.

It is an amenable number.

21201012210121 is a deficient number, since it is larger than the sum of its proper divisors (7022531079).

21201012210121 is an equidigital number, since it uses as much as digits as its factorization.

21201012210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7022531078.

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

Adding to 21201012210121 its reverse (12101221010212), we get a palindrome (33302233220333).

The spelling of 21201012210121 in words is "twenty-one trillion, two hundred one billion, twelve million, two hundred ten thousand, one hundred twenty-one".