243121242123 has 8 divisors (see below), whose sum is σ = 360179618000. Its totient is φ = 162080828064.

The previous prime is 243121242073. The next prime is 243121242157. The reversal of 243121242123 is 321242121342.

243121242123 is a `hidden beast` number, since 2 + 4 + 3 + 1 + 212 + 421 + 23 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-243121242123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 9004490449 = 243121242123 / (2 + 4 + 3 + 1 + 2 + 1 + 2 + 4 + 2 + 1 + 2 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243121242323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4502245198 + ... + 4502245251.

It is an arithmetic number, because the mean of its divisors is an integer number (45022452250).

Almost surely, 2^243121242123 is an apocalyptic number.

243121242123 is a deficient number, since it is larger than the sum of its proper divisors (117058375877).

243121242123 is an equidigital number, since it uses as much as digits as its factorization.

243121242123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9004490458 (or 9004490452 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

Adding to 243121242123 its reverse (321242121342), we get a palindrome (564363363465).

The spelling of 243121242123 in words is "two hundred forty-three billion, one hundred twenty-one million, two hundred forty-two thousand, one hundred twenty-three".