243959 has 4 divisors (see below), whose sum is σ = 248616. Its totient is φ = 239304.

The previous prime is 243953. The next prime is 243973. The reversal of 243959 is 959342.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 243959 - 2⁸ = 243703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243953) 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 in 3 ways as a sum of consecutive naturals, for example, 2249 + ... + 2354.

It is an arithmetic number, because the mean of its divisors is an integer number (62154).

2²⁴³⁹⁵⁹ is an apocalyptic number.

243959 is a deficient number, since it is larger than the sum of its proper divisors (4657).

243959 is an equidigital number, since it uses as much as digits as its factorization.

243959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4656.

The product of its digits is 9720, while the sum is 32.

The square root of 243959 is about 493.9220586287. The cubic root of 243959 is about 62.4844974884.

The spelling of 243959 in words is "two hundred forty-three thousand, nine hundred fifty-nine".