21200012120121 has 16 divisors (see below), whose sum is σ = 28659101644800. Its totient is φ = 13937564663568.

The previous prime is 21200012120113. The next prime is 21200012120137. The reversal of 21200012120121 is 12102121000212.

It is not a de Polignac number, because 21200012120121 - 2³ = 21200012120113 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21200012120121.

It is not an unprimeable number, because it can be changed into a prime (21200012120921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53885941 + ... + 54277938.

It is an arithmetic number, because the mean of its divisors is an integer number (1791193852800).

Almost surely, 2^{21200012120121} is an apocalyptic number.

It is an amenable number.

21200012120121 is a deficient number, since it is larger than the sum of its proper divisors (7459089524679).

21200012120121 is a wasteful number, since it uses less digits than its factorization.

21200012120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108164788.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21200012120121 its reverse (12102121000212), we get a palindrome (33302133120333).

The spelling of 21200012120121 in words is "twenty-one trillion, two hundred billion, twelve million, one hundred twenty thousand, one hundred twenty-one".