243243405205 has 4 divisors (see below), whose sum is σ = 291892086252. Its totient is φ = 194594724160.

The previous prime is 243243405199. The next prime is 243243405263. The reversal of 243243405205 is 502504342342.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 189657637009 + 53585768196 = 435497^2 + 231486^2 .

It is not a de Polignac number, because 243243405205 - 2³¹ = 241095921557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24324340516 + ... + 24324340525.

It is an arithmetic number, because the mean of its divisors is an integer number (72973021563).

Almost surely, 2^243243405205 is an apocalyptic number.

It is an amenable number.

243243405205 is a deficient number, since it is larger than the sum of its proper divisors (48648681047).

243243405205 is an equidigital number, since it uses as much as digits as its factorization.

243243405205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48648681046.

The product of its (nonzero) digits is 115200, while the sum is 34.

Adding to 243243405205 its reverse (502504342342), we get a palindrome (745747747547).

The spelling of 243243405205 in words is "two hundred forty-three billion, two hundred forty-three million, four hundred five thousand, two hundred five".