243945817 has 4 divisors (see below), whose sum is σ = 244031760. Its totient is φ = 243859876.

The previous prime is 243945811. The next prime is 243945853. The reversal of 243945817 is 718549342.

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 243945817 - 2³ = 243945809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243945811) 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, 38563 + ... + 44440.

It is an arithmetic number, because the mean of its divisors is an integer number (61007940).

Almost surely, 2^243945817 is an apocalyptic number.

It is an amenable number.

243945817 is a deficient number, since it is larger than the sum of its proper divisors (85943).

243945817 is an equidigital number, since it uses as much as digits as its factorization.

243945817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85942.

The product of its digits is 241920, while the sum is 43.

The square root of 243945817 is about 15618.7648999529. The cubic root of 243945817 is about 624.8337196053.

The spelling of 243945817 in words is "two hundred forty-three million, nine hundred forty-five thousand, eight hundred seventeen".