243319957 has 2 divisors, whose sum is σ = 243319958. Its totient is φ = 243319956.

The previous prime is 243319933. The next prime is 243319969. The reversal of 243319957 is 759913342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166564836 + 76755121 = 12906^2 + 8761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243319957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243319907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121659978 + 121659979.

It is an arithmetic number, because the mean of its divisors is an integer number (121659979).

Almost surely, 2^243319957 is an apocalyptic number.

It is an amenable number.

243319957 is a deficient number, since it is larger than the sum of its proper divisors (1).

243319957 is an equidigital number, since it uses as much as digits as its factorization.

243319957 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 204120, while the sum is 43.

The square root of 243319957 is about 15598.7165177139. The cubic root of 243319957 is about 624.2989104917.

The spelling of 243319957 in words is "two hundred forty-three million, three hundred nineteen thousand, nine hundred fifty-seven".