243121242313 has 4 divisors (see below), whose sum is σ = 245528383428. Its totient is φ = 240714101200.

The previous prime is 243121242281. The next prime is 243121242323. The reversal of 243121242313 is 313242121342.

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 169635249424 + 73485992889 = 411868^2 + 271083^2 .

It is a cyclic number.

It is not a de Polignac number, because 243121242313 - 2⁵ = 243121242281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243121242323) 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, 1203570406 + ... + 1203570607.

It is an arithmetic number, because the mean of its divisors is an integer number (61382095857).

Almost surely, 2^243121242313 is an apocalyptic number.

It is an amenable number.

243121242313 is a deficient number, since it is larger than the sum of its proper divisors (2407141115).

243121242313 is a wasteful number, since it uses less digits than its factorization.

243121242313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2407141114.

The product of its digits is 6912, while the sum is 28.

Adding to 243121242313 its reverse (313242121342), we get a palindrome (556363363655).

The spelling of 243121242313 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty-two thousand, three hundred thirteen".