2121442121 has 4 divisors (see below), whose sum is σ = 2246232852. Its totient is φ = 1996651392.

The previous prime is 2121442117. The next prime is 2121442139. The reversal of 2121442121 is 1212441212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1809566521 + 311875600 = 42539^2 + 17660^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121442121 - 2² = 2121442117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121442093 and 2121442102.

It is not an unprimeable number, because it can be changed into a prime (2121442111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62395340 + ... + 62395373.

It is an arithmetic number, because the mean of its divisors is an integer number (561558213).

Almost surely, 2^2121442121 is an apocalyptic number.

It is an amenable number.

2121442121 is a deficient number, since it is larger than the sum of its proper divisors (124790731).

2121442121 is a wasteful number, since it uses less digits than its factorization.

2121442121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124790730.

The product of its digits is 256, while the sum is 20.

The square root of 2121442121 is about 46059.1155038826. The cubic root of 2121442121 is about 1284.9228800987.

Adding to 2121442121 its reverse (1212441212), we get a palindrome (3333883333).

Subtracting from 2121442121 its reverse (1212441212), we obtain a palindrome (909000909).

The spelling of 2121442121 in words is "two billion, one hundred twenty-one million, four hundred forty-two thousand, one hundred twenty-one".