243121243505 has 64 divisors (see below), whose sum is σ = 347484487680. Its totient is φ = 159858316800.

The previous prime is 243121243459. The next prime is 243121243513. The reversal of 243121243505 is 505342121342.

It is a de Polignac number, because none of the positive numbers 2^k-243121243505 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17016965 + ... + 17031245.

It is an arithmetic number, because the mean of its divisors is an integer number (5429445120).

Almost surely, 2^243121243505 is an apocalyptic number.

It is an amenable number.

243121243505 is a deficient number, since it is larger than the sum of its proper divisors (104363244175).

243121243505 is a wasteful number, since it uses less digits than its factorization.

243121243505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14550.

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 243121243505 its reverse (505342121342), we get a palindrome (748463364847).

The spelling of 243121243505 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty-three thousand, five hundred five".