243021313 has 2 divisors, whose sum is σ = 243021314. Its totient is φ = 243021312.

The previous prime is 243021299. The next prime is 243021397. The reversal of 243021313 is 313120342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230827249 + 12194064 = 15193^2 + 3492^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243021313 is a prime.

It is equal to p_13318012 and since 243021313 and 13318012 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (243022313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121510656 + 121510657.

It is an arithmetic number, because the mean of its divisors is an integer number (121510657).

Almost surely, 2^243021313 is an apocalyptic number.

It is an amenable number.

243021313 is a deficient number, since it is larger than the sum of its proper divisors (1).

243021313 is an equidigital number, since it uses as much as digits as its factorization.

243021313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 243021313 is about 15589.1408679247. The cubic root of 243021313 is about 624.0433903437.

Adding to 243021313 its reverse (313120342), we get a palindrome (556141655).

The spelling of 243021313 in words is "two hundred forty-three million, twenty-one thousand, three hundred thirteen".