243939313 has 2 divisors, whose sum is σ = 243939314. Its totient is φ = 243939312.

The previous prime is 243939287. The next prime is 243939331. The reversal of 243939313 is 313939342.

It is a happy number.

Together with next prime (243939331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242331489 + 1607824 = 15567^2 + 1268^2 .

It is a cyclic number.

It is not a de Polignac number, because 243939313 - 2¹⁷ = 243808241 is a prime.

It is not a weakly prime, because it can be changed into another prime (243939343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121969656 + 121969657.

It is an arithmetic number, because the mean of its divisors is an integer number (121969657).

Almost surely, 2^243939313 is an apocalyptic number.

It is an amenable number.

243939313 is a deficient number, since it is larger than the sum of its proper divisors (1).

243939313 is an equidigital number, since it uses as much as digits as its factorization.

243939313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 37.

The square root of 243939313 is about 15618.5566874792. The cubic root of 243939313 is about 624.8281665215.

The spelling of 243939313 in words is "two hundred forty-three million, nine hundred thirty-nine thousand, three hundred thirteen".