21221223321121 has 16 divisors (see below), whose sum is σ = 22441552293888. Its totient is φ = 20027466043200.

The previous prime is 21221223321079. The next prime is 21221223321157. The reversal of 21221223321121 is 12112332212212.

It is a cyclic number.

It is not a de Polignac number, because 21221223321121 - 2¹¹ = 21221223319073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21221223321821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19540510 + ... + 20597911.

It is an arithmetic number, because the mean of its divisors is an integer number (1402597018368).

Almost surely, 2^{21221223321121} is an apocalyptic number.

It is an amenable number.

21221223321121 is a deficient number, since it is larger than the sum of its proper divisors (1220328972767).

21221223321121 is a wasteful number, since it uses less digits than its factorization.

21221223321121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40138752.

The product of its digits is 1152, while the sum is 25.

Adding to 21221223321121 its reverse (12112332212212), we get a palindrome (33333555533333).

The spelling of 21221223321121 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-three million, three hundred twenty-one thousand, one hundred twenty-one".