243931409 has 4 divisors (see below), whose sum is σ = 243980016. Its totient is φ = 243882804.

The previous prime is 243931393. The next prime is 243931421. The reversal of 243931409 is 904139342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243931409 - 2⁴ = 243931393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243931459) 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 3 ways as a sum of consecutive naturals, for example, 15779 + ... + 27144.

It is an arithmetic number, because the mean of its divisors is an integer number (60995004).

Almost surely, 2^243931409 is an apocalyptic number.

It is an amenable number.

243931409 is a deficient number, since it is larger than the sum of its proper divisors (48607).

243931409 is an equidigital number, since it uses as much as digits as its factorization.

243931409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48606.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 243931409 is about 15618.3036530860. The cubic root of 243931409 is about 624.8214179917.

The spelling of 243931409 in words is "two hundred forty-three million, nine hundred thirty-one thousand, four hundred nine".