243213439 has 4 divisors (see below), whose sum is σ = 277958224. Its totient is φ = 208468656.

The previous prime is 243213409. The next prime is 243213457. The reversal of 243213439 is 934312342.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243213439 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243213439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243213409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17372382 + ... + 17372395.

It is an arithmetic number, because the mean of its divisors is an integer number (69489556).

Almost surely, 2^243213439 is an apocalyptic number.

243213439 is a deficient number, since it is larger than the sum of its proper divisors (34744785).

243213439 is an equidigital number, since it uses as much as digits as its factorization.

243213439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34744784.

The product of its digits is 15552, while the sum is 31.

The square root of 243213439 is about 15595.3018245881. The cubic root of 243213439 is about 624.2077975687.

The spelling of 243213439 in words is "two hundred forty-three million, two hundred thirteen thousand, four hundred thirty-nine".