243123454521 has 6 divisors (see below), whose sum is σ = 351178323210. Its totient is φ = 162082303008.

The previous prime is 243123454493. The next prime is 243123454589. The reversal of 243123454521 is 125454321342.

It is a happy number.

243123454521 is a `hidden beast` number, since 2 + 4 + 3 + 123 + 4 + 5 + 4 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 242397690921 + 725763600 = 492339^2 + 26940^2 .

It is not a de Polignac number, because 243123454521 - 2²² = 243119260217 is a prime.

It is not an unprimeable number, because it can be changed into a prime (243123454421) 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 5 ways as a sum of consecutive naturals, for example, 13506858576 + ... + 13506858593.

It is an arithmetic number, because the mean of its divisors is an integer number (58529720535).

Almost surely, 2^243123454521 is an apocalyptic number.

It is an amenable number.

243123454521 is a deficient number, since it is larger than the sum of its proper divisors (108054868689).

243123454521 is a wasteful number, since it uses less digits than its factorization.

243123454521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27013717175 (or 27013717172 counting only the distinct ones).

The product of its digits is 115200, while the sum is 36.

Adding to 243123454521 its reverse (125454321342), we get a palindrome (368577775863).

The spelling of 243123454521 in words is "two hundred forty-three billion, one hundred twenty-three million, four hundred fifty-four thousand, five hundred twenty-one".