2121113121 has 4 divisors (see below), whose sum is σ = 2828150832. Its totient is φ = 1414075412.

The previous prime is 2121113101. The next prime is 2121113129. The reversal of 2121113121 is 1213111212.

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 2121113121 - 2⁷ = 2121112993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2121113121.

It is not an unprimeable number, because it can be changed into a prime (2121113129) 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, 353518851 + ... + 353518856.

It is an arithmetic number, because the mean of its divisors is an integer number (707037708).

Almost surely, 2^2121113121 is an apocalyptic number.

It is an amenable number.

2121113121 is a deficient number, since it is larger than the sum of its proper divisors (707037711).

2121113121 is an equidigital number, since it uses as much as digits as its factorization.

2121113121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707037710.

The product of its digits is 24, while the sum is 15.

The square root of 2121113121 is about 46055.5438682467. The cubic root of 2121113121 is about 1284.8564533540.

Adding to 2121113121 its reverse (1213111212), we get a palindrome (3334224333).

The spelling of 2121113121 in words is "two billion, one hundred twenty-one million, one hundred thirteen thousand, one hundred twenty-one".