2143243121 has 4 divisors (see below), whose sum is σ = 2143368612. Its totient is φ = 2143117632.

The previous prime is 2143243117. The next prime is 2143243163. The reversal of 2143243121 is 1213423412.

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 1807950400 + 335292721 = 42520^2 + 18311^2 .

It is a cyclic number.

It is not a de Polignac number, because 2143243121 - 2² = 2143243117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2143243321) 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, 32156 + ... + 72941.

It is an arithmetic number, because the mean of its divisors is an integer number (535842153).

Almost surely, 2^2143243121 is an apocalyptic number.

It is an amenable number.

2143243121 is a deficient number, since it is larger than the sum of its proper divisors (125491).

2143243121 is a wasteful number, since it uses less digits than its factorization.

2143243121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125490.

The product of its digits is 1152, while the sum is 23.

The square root of 2143243121 is about 46295.1738413412. The cubic root of 2143243121 is about 1289.3093915773.

Adding to 2143243121 its reverse (1213423412), we get a palindrome (3356666533).

The spelling of 2143243121 in words is "two billion, one hundred forty-three million, two hundred forty-three thousand, one hundred twenty-one".