20121112121 has 4 divisors (see below), whose sum is σ = 21950304144. Its totient is φ = 18291920100.

The previous prime is 20121112111. The next prime is 20121112159. The reversal of 20121112121 is 12121112102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20121112121 - 2²² = 20116917817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121112096 and 20121112105.

It is not an unprimeable number, because it can be changed into a prime (20121112111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914595995 + ... + 914596016.

It is an arithmetic number, because the mean of its divisors is an integer number (5487576036).

Almost surely, 2^20121112121 is an apocalyptic number.

It is an amenable number.

20121112121 is a deficient number, since it is larger than the sum of its proper divisors (1829192023).

20121112121 is a wasteful number, since it uses less digits than its factorization.

20121112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829192022.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20121112121 its reverse (12121112102), we get a palindrome (32242224223).

The spelling of 20121112121 in words is "twenty billion, one hundred twenty-one million, one hundred twelve thousand, one hundred twenty-one".