21111122021121 has 12 divisors (see below), whose sum is σ = 33266010457680. Its totient is φ = 12794619406680.

The previous prime is 21111122021117. The next prime is 21111122021141. The reversal of 21111122021121 is 12112022111112.

It is a happy number.

21111122021121 is a `hidden beast` number, since 211 + 1 + 1 + 1 + 220 + 211 + 21 = 666.

It is not a de Polignac number, because 21111122021121 - 2² = 21111122021117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111122021094 and 21111122021103.

It is not an unprimeable number, because it can be changed into a prime (21111122021141) 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, 106621828291 + ... + 106621828488.

It is an arithmetic number, because the mean of its divisors is an integer number (2772167538140).

Almost surely, 2^{21111122021121} is an apocalyptic number.

It is an amenable number.

21111122021121 is a deficient number, since it is larger than the sum of its proper divisors (12154888436559).

21111122021121 is a wasteful number, since it uses less digits than its factorization.

21111122021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213243656796 (or 213243656793 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21111122021121 its reverse (12112022111112), we get a palindrome (33223144132233).

The spelling of 21111122021121 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-two million, twenty-one thousand, one hundred twenty-one".