243435809187209 has 2 divisors, whose sum is σ = 243435809187210. Its totient is φ = 243435809187208.

The previous prime is 243435809187191. The next prime is 243435809187223. The reversal of 243435809187209 is 902781908534342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179570586156025 + 63865223031184 = 13400395^2 + 7991572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243435809187209 is a prime.

It is not a weakly prime, because it can be changed into another prime (243435809187239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121717904593604 + 121717904593605.

It is an arithmetic number, because the mean of its divisors is an integer number (121717904593605).

Almost surely, 2^{243435809187209} is an apocalyptic number.

It is an amenable number.

243435809187209 is a deficient number, since it is larger than the sum of its proper divisors (1).

243435809187209 is an equidigital number, since it uses as much as digits as its factorization.

243435809187209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104509440, while the sum is 65.

The spelling of 243435809187209 in words is "two hundred forty-three trillion, four hundred thirty-five billion, eight hundred nine million, one hundred eighty-seven thousand, two hundred nine".