21020122012221 has 12 divisors (see below), whose sum is σ = 30362442264960. Its totient is φ = 14013394458120.

The previous prime is 21020122012207. The next prime is 21020122012231. The reversal of 21020122012221 is 12221022102012.

It is a happy number.

21020122012221 is a `hidden beast` number, since 2 + 10 + 201 + 220 + 12 + 221 = 666.

It is not a de Polignac number, because 21020122012221 - 2¹³ = 21020122004029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21020122012194 and 21020122012203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020122012231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7584340 + ... + 9978098.

It is an arithmetic number, because the mean of its divisors is an integer number (2530203522080).

Almost surely, 2^{21020122012221} is an apocalyptic number.

It is an amenable number.

21020122012221 is a deficient number, since it is larger than the sum of its proper divisors (9342320252739).

21020122012221 is a wasteful number, since it uses less digits than its factorization.

21020122012221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3369456 (or 3369453 counting only the distinct ones).

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

Adding to 21020122012221 its reverse (12221022102012), we get a palindrome (33241144114233).

The spelling of 21020122012221 in words is "twenty-one trillion, twenty billion, one hundred twenty-two million, twelve thousand, two hundred twenty-one".