243240031 has 4 divisors (see below), whose sum is σ = 243499464. Its totient is φ = 242980600.

The previous prime is 243239989. The next prime is 243240047. The reversal of 243240031 is 130042342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130042342 = 2 ⋅65021171.

It is a cyclic number.

It is not a de Polignac number, because 243240031 - 2¹¹ = 243237983 is a prime.

It is a super-2 number, since 2×243240031² = 118331425361761922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 243239990 and 243240008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243240061) 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, 128305 + ... + 130186.

It is an arithmetic number, because the mean of its divisors is an integer number (60874866).

Almost surely, 2^243240031 is an apocalyptic number.

243240031 is a deficient number, since it is larger than the sum of its proper divisors (259433).

243240031 is an equidigital number, since it uses as much as digits as its factorization.

243240031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259432.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 243240031 is about 15596.1543657403. The cubic root of 243240031 is about 624.2305462141.

Adding to 243240031 its reverse (130042342), we get a palindrome (373282373).

The spelling of 243240031 in words is "two hundred forty-three million, two hundred forty thousand, thirty-one".