21200222121121 has 4 divisors (see below), whose sum is σ = 21200371395732. Its totient is φ = 21200072846512.

The previous prime is 21200222120989. The next prime is 21200222121131. The reversal of 21200222121121 is 12112122200212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8123782550625 + 13076439570496 = 2850225^2 + 3616136^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200222121121 - 2³¹ = 21198074637473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21200222121131) 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, 74424070 + ... + 74708383.

It is an arithmetic number, because the mean of its divisors is an integer number (5300092848933).

Almost surely, 2^{21200222121121} is an apocalyptic number.

It is an amenable number.

21200222121121 is a deficient number, since it is larger than the sum of its proper divisors (149274611).

21200222121121 is a wasteful number, since it uses less digits than its factorization.

21200222121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149274610.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21200222121121 its reverse (12112122200212), we get a palindrome (33312344321333).

The spelling of 21200222121121 in words is "twenty-one trillion, two hundred billion, two hundred twenty-two million, one hundred twenty-one thousand, one hundred twenty-one".