243121313 has 8 divisors (see below), whose sum is σ = 252076800. Its totient is φ = 234235440.

The previous prime is 243121309. The next prime is 243121327. The reversal of 243121313 is 313121342.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 243121313 - 2² = 243121309 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243121343) 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 7 ways as a sum of consecutive naturals, for example, 10238 + ... + 24311.

It is an arithmetic number, because the mean of its divisors is an integer number (31509600).

Almost surely, 2^243121313 is an apocalyptic number.

It is an amenable number.

243121313 is a deficient number, since it is larger than the sum of its proper divisors (8955487).

243121313 is a wasteful number, since it uses less digits than its factorization.

243121313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34807.

The product of its digits is 432, while the sum is 20.

The square root of 243121313 is about 15592.3478988894. The cubic root of 243121313 is about 624.1289737585.

Adding to 243121313 its reverse (313121342), we get a palindrome (556242655).

The spelling of 243121313 in words is "two hundred forty-three million, one hundred twenty-one thousand, three hundred thirteen".