21222001022121 has 6 divisors (see below), whose sum is σ = 30654001476410. Its totient is φ = 14148000681408.

The previous prime is 21222001022093. The next prime is 21222001022129. The reversal of 21222001022121 is 12122010022212.

It is a happy number.

21222001022121 is a `hidden beast` number, since 212 + 2 + 200 + 10 + 221 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 15014354026896 + 6207646995225 = 3874836^2 + 2491515^2 .

It is not a de Polignac number, because 21222001022121 - 2¹³ = 21222001013929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21222001022094 and 21222001022103.

It is not an unprimeable number, because it can be changed into a prime (21222001022129) 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, 1179000056776 + ... + 1179000056793.

Almost surely, 2^{21222001022121} is an apocalyptic number.

It is an amenable number.

21222001022121 is a deficient number, since it is larger than the sum of its proper divisors (9432000454289).

21222001022121 is a wasteful number, since it uses less digits than its factorization.

21222001022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2358000113575 (or 2358000113572 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21222001022121 its reverse (12122010022212), we get a palindrome (33344011044333).

Subtracting from 21222001022121 its reverse (12122010022212), we obtain a palindrome (9099990999909).

The spelling of 21222001022121 in words is "twenty-one trillion, two hundred twenty-two billion, one million, twenty-two thousand, one hundred twenty-one".