21200211221121 has 6 divisors (see below), whose sum is σ = 30622527319410. Its totient is φ = 14133474147408.

The previous prime is 21200211221081. The next prime is 21200211221141. The reversal of 21200211221121 is 12112211200212.

21200211221121 is a `hidden beast` number, since 21 + 200 + 211 + 2 + 211 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 14260358611521 + 6939852609600 = 3776289^2 + 2634360^2 .

It is not a de Polignac number, because 21200211221121 - 2¹¹ = 21200211219073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200211221094 and 21200211221103.

It is not an unprimeable number, because it can be changed into a prime (21200211221141) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1177789512276 + ... + 1177789512293.

It is an arithmetic number, because the mean of its divisors is an integer number (5103754553235).

Almost surely, 2^{21200211221121} is an apocalyptic number.

It is an amenable number.

21200211221121 is a deficient number, since it is larger than the sum of its proper divisors (9422316098289).

21200211221121 is a wasteful number, since it uses less digits than its factorization.

21200211221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2355579024575 (or 2355579024572 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21200211221121 its reverse (12112211200212), we get a palindrome (33312422421333).

The spelling of 21200211221121 in words is "twenty-one trillion, two hundred billion, two hundred eleven million, two hundred twenty-one thousand, one hundred twenty-one".