243123504531 has 4 divisors (see below), whose sum is σ = 324164672712. Its totient is φ = 162082336352.

The previous prime is 243123504497. The next prime is 243123504539. The reversal of 243123504531 is 135405321342.

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

It is a cyclic number.

It is not a de Polignac number, because 243123504531 - 2³⁴ = 225943635347 is a prime.

It is a super-2 number, since 2×243123504531² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 243123504492 and 243123504501.

It is not an unprimeable number, because it can be changed into a prime (243123504539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40520584086 + ... + 40520584091.

It is an arithmetic number, because the mean of its divisors is an integer number (81041168178).

Almost surely, 2^243123504531 is an apocalyptic number.

243123504531 is a deficient number, since it is larger than the sum of its proper divisors (81041168181).

243123504531 is an equidigital number, since it uses as much as digits as its factorization.

243123504531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81041168180.

The product of its (nonzero) digits is 43200, while the sum is 33.

Adding to 243123504531 its reverse (135405321342), we get a palindrome (378528825873).

The spelling of 243123504531 in words is "two hundred forty-three billion, one hundred twenty-three million, five hundred four thousand, five hundred thirty-one".