243243404505 has 12 divisors (see below), whose sum is σ = 421621901220. Its totient is φ = 129729815712.

The previous prime is 243243404489. The next prime is 243243404519. The reversal of 243243404505 is 505404342342.

243243404505 is a `hidden beast` number, since 2 + 4 + 3 + 243 + 404 + 5 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 186893665344 + 56349739161 = 432312^2 + 237381^2 .

It is not a de Polignac number, because 243243404505 - 2⁴ = 243243404489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243243404505.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2702704450 + ... + 2702704539.

It is an arithmetic number, because the mean of its divisors is an integer number (35135158435).

Almost surely, 2^243243404505 is an apocalyptic number.

It is an amenable number.

243243404505 is a deficient number, since it is larger than the sum of its proper divisors (178378496715).

243243404505 is a wasteful number, since it uses less digits than its factorization.

243243404505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5405409000 (or 5405408997 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 36.

Adding to 243243404505 its reverse (505404342342), we get a palindrome (748647746847).

The spelling of 243243404505 in words is "two hundred forty-three billion, two hundred forty-three million, four hundred four thousand, five hundred five".