243640949 has 2 divisors, whose sum is σ = 243640950. Its totient is φ = 243640948.

The previous prime is 243640879. The next prime is 243640963. The reversal of 243640949 is 949046342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 243578449 + 62500 = 15607^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 243640949 - 2⁸ = 243640693 is a prime.

It is a Chen prime.

It is a zygodrome in base 5.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243640979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121820474 + 121820475.

It is an arithmetic number, because the mean of its divisors is an integer number (121820475).

Almost surely, 2^243640949 is an apocalyptic number.

It is an amenable number.

243640949 is a deficient number, since it is larger than the sum of its proper divisors (1).

243640949 is an equidigital number, since it uses as much as digits as its factorization.

243640949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 41.

The square root of 243640949 is about 15609.0021782304. The cubic root of 243640949 is about 624.5733185884.

The spelling of 243640949 in words is "two hundred forty-three million, six hundred forty thousand, nine hundred forty-nine".