243123353505 has 24 divisors (see below), whose sum is σ = 429365020968. Its totient is φ = 127219262976.

The previous prime is 243123353479. The next prime is 243123353507. The reversal of 243123353505 is 505353321342.

243123353505 is a `hidden beast` number, since 2 + 4 + 312 + 335 + 3 + 5 + 0 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 45312785424 + 197810568081 = 212868^2 + 444759^2 .

It is not a de Polignac number, because 243123353505 - 2¹² = 243123349409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243123353505.

It is not an unprimeable number, because it can be changed into a prime (243123353507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50966872 + ... + 50971641.

It is an arithmetic number, because the mean of its divisors is an integer number (17890209207).

Almost surely, 2^243123353505 is an apocalyptic number.

It is an amenable number.

243123353505 is a deficient number, since it is larger than the sum of its proper divisors (186241667463).

243123353505 is a wasteful number, since it uses less digits than its factorization.

243123353505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101938577 (or 101938574 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 36.

Adding to 243123353505 its reverse (505353321342), we get a palindrome (748476674847).

The spelling of 243123353505 in words is "two hundred forty-three billion, one hundred twenty-three million, three hundred fifty-three thousand, five hundred five".