243688559 has 2 divisors, whose sum is σ = 243688560. Its totient is φ = 243688558.

The previous prime is 243688531. The next prime is 243688573. The reversal of 243688559 is 955886342.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 243688559 - 2²⁰ = 242639983 is a prime.

It is a super-2 number, since 2×243688559² = 118768227574992962, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243688579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121844279 + 121844280.

It is an arithmetic number, because the mean of its divisors is an integer number (121844280).

Almost surely, 2^243688559 is an apocalyptic number.

243688559 is a deficient number, since it is larger than the sum of its proper divisors (1).

243688559 is an equidigital number, since it uses as much as digits as its factorization.

243688559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2073600, while the sum is 50.

The square root of 243688559 is about 15610.5271852042. The cubic root of 243688559 is about 624.6139986672.

The spelling of 243688559 in words is "two hundred forty-three million, six hundred eighty-eight thousand, five hundred fifty-nine".