243972909 has 6 divisors (see below), whose sum is σ = 352405326. Its totient is φ = 162648600.

The previous prime is 243972887. The next prime is 243972913. The reversal of 243972909 is 909279342.

It can be written as a sum of positive squares in only one way, i.e., 215649225 + 28323684 = 14685^2 + 5322^2 .

It is not a de Polignac number, because 243972909 - 2²⁰ = 242924333 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243972979) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13554042 + ... + 13554059.

It is an arithmetic number, because the mean of its divisors is an integer number (58734221).

Almost surely, 2^243972909 is an apocalyptic number.

It is an amenable number.

243972909 is a deficient number, since it is larger than the sum of its proper divisors (108432417).

243972909 is a wasteful number, since it uses less digits than its factorization.

243972909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27108107 (or 27108104 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The square root of 243972909 is about 15619.6321659634. The cubic root of 243972909 is about 624.8568495619.

The spelling of 243972909 in words is "two hundred forty-three million, nine hundred seventy-two thousand, nine hundred nine".