2121112112121 has 24 divisors (see below), whose sum is σ = 3276173187144. Its totient is φ = 1317716697600.

The previous prime is 2121112112113. The next prime is 2121112112179. The reversal of 2121112112121 is 1212112111212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 819206010000 + 1301906102121 = 905100^2 + 1141011^2 .

It is not a de Polignac number, because 2121112112121 - 2³ = 2121112112113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121112112094 and 2121112112103.

It is not an unprimeable number, because it can be changed into a prime (2121112112221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68615626 + ... + 68646531.

It is an arithmetic number, because the mean of its divisors is an integer number (136507216131).

Almost surely, 2^{2121112112121} is an apocalyptic number.

It is an amenable number.

2121112112121 is a deficient number, since it is larger than the sum of its proper divisors (1155061075023).

2121112112121 is a wasteful number, since it uses less digits than its factorization.

2121112112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137262281 (or 137262278 counting only the distinct ones).

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

Adding to 2121112112121 its reverse (1212112111212), we get a palindrome (3333224223333).

Subtracting from 2121112112121 its reverse (1212112111212), we obtain a palindrome (909000000909).

It can be divided in two parts, 212111 and 2112121, that added together give a palindrome (2324232).

The spelling of 2121112112121 in words is "two trillion, one hundred twenty-one billion, one hundred twelve million, one hundred twelve thousand, one hundred twenty-one".