4243215121 has 2 divisors, whose sum is σ = 4243215122. Its totient is φ = 4243215120.

The previous prime is 4243215073. The next prime is 4243215133. The reversal of 4243215121 is 1215123424.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4233324096 + 9891025 = 65064^2 + 3145^2 .

It is a cyclic number.

It is not a de Polignac number, because 4243215121 - 2²⁹ = 3706344209 is a prime.

It is not a weakly prime, because it can be changed into another prime (4243215721) 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 as a sum of consecutive naturals, namely, 2121607560 + 2121607561.

It is an arithmetic number, because the mean of its divisors is an integer number (2121607561).

Almost surely, 2^4243215121 is an apocalyptic number.

It is an amenable number.

4243215121 is a deficient number, since it is larger than the sum of its proper divisors (1).

4243215121 is an equidigital number, since it uses as much as digits as its factorization.

4243215121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 25.

The square root of 4243215121 is about 65139.9656201936. The cubic root of 4243215121 is about 1618.9434660794.

Adding to 4243215121 its reverse (1215123424), we get a palindrome (5458338545).

The spelling of 4243215121 in words is "four billion, two hundred forty-three million, two hundred fifteen thousand, one hundred twenty-one".