21102220122121 has 16 divisors (see below), whose sum is σ = 21187325149200. Its totient is φ = 21017236331520.

The previous prime is 21102220122103. The next prime is 21102220122163. The reversal of 21102220122121 is 12122102220112.

It can be written as a sum of positive squares in 8 ways, for example, as 920517438096 + 20181702684025 = 959436^2 + 4492405^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102220122121 - 2¹¹ = 21102220120073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102220129121) 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, 2871437355 + ... + 2871444703.

It is an arithmetic number, because the mean of its divisors is an integer number (1324207821825).

Almost surely, 2^{21102220122121} is an apocalyptic number.

It is an amenable number.

21102220122121 is a deficient number, since it is larger than the sum of its proper divisors (85105027079).

21102220122121 is a wasteful number, since it uses less digits than its factorization.

21102220122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14076.

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

Adding to 21102220122121 its reverse (12122102220112), we get a palindrome (33224322342233).

The spelling of 21102220122121 in words is "twenty-one trillion, one hundred two billion, two hundred twenty million, one hundred twenty-two thousand, one hundred twenty-one".