21110112212121 has 12 divisors (see below), whose sum is σ = 30686603316772. Its totient is φ = 13983768598176.

The previous prime is 21110112212117. The next prime is 21110112212257. The reversal of 21110112212121 is 12121221101112.

It is a happy number.

21110112212121 is a `hidden beast` number, since 211 + 10 + 11 + 221 + 212 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11661644457225 + 9448467754896 = 3414915^2 + 3073836^2 .

It is not a de Polignac number, because 21110112212121 - 2² = 21110112212117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110112212094 and 21110112212103.

It is not an unprimeable number, because it can be changed into a prime (21110112211121) 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, 7469960446 + ... + 7469963271.

Almost surely, 2^{21110112212121} is an apocalyptic number.

It is an amenable number.

21110112212121 is a deficient number, since it is larger than the sum of its proper divisors (9576491104651).

21110112212121 is a wasteful number, since it uses less digits than its factorization.

21110112212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14939923880 (or 14939923877 counting only the distinct ones).

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

Adding to 21110112212121 its reverse (12121221101112), we get a palindrome (33231333313233).

The spelling of 21110112212121 in words is "twenty-one trillion, one hundred ten billion, one hundred twelve million, two hundred twelve thousand, one hundred twenty-one".