21122211121 has 16 divisors (see below), whose sum is σ = 23790348288. Its totient is φ = 18586108800.

The previous prime is 21122211107. The next prime is 21122211157. The reversal of 21122211121 is 12111222112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122211121 is a prime.

It is a super-2 number, since 2×21122211121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122211095 and 21122211104.

It is not an unprimeable number, because it can be changed into a prime (21122211191) 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, 127110 + ... + 241663.

It is an arithmetic number, because the mean of its divisors is an integer number (1486896768).

Almost surely, 2^21122211121 is an apocalyptic number.

It is an amenable number.

21122211121 is a deficient number, since it is larger than the sum of its proper divisors (2668137167).

21122211121 is a wasteful number, since it uses less digits than its factorization.

21122211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368952.

The product of its digits is 32, while the sum is 16.

Adding to 21122211121 its reverse (12111222112), we get a palindrome (33233433233).

The spelling of 21122211121 in words is "twenty-one billion, one hundred twenty-two million, two hundred eleven thousand, one hundred twenty-one".