243939 has 16 divisors (see below), whose sum is σ = 349184. Its totient is φ = 151200.

The previous prime is 243931. The next prime is 243953. The reversal of 243939 is 939342.

It is not a de Polignac number, because 243939 - 2³ = 243931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (243931) 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 in 15 ways as a sum of consecutive naturals, for example, 3969 + ... + 4029.

It is an arithmetic number, because the mean of its divisors is an integer number (21824).

2²⁴³⁹³⁹ is an apocalyptic number.

243939 is a deficient number, since it is larger than the sum of its proper divisors (105245).

243939 is a wasteful number, since it uses less digits than its factorization.

243939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138.

The product of its digits is 5832, while the sum is 30.

The square root of 243939 is about 493.9018121044. The cubic root of 243939 is about 62.4827899281.

It can be divided in two parts, 2 and 43939, that multiplied together give a palindrome (87878).

The spelling of 243939 in words is "two hundred forty-three thousand, nine hundred thirty-nine".