243123513021 has 24 divisors (see below), whose sum is σ = 365641206840. Its totient is φ = 155536819200.

The previous prime is 243123513007. The next prime is 243123513043. The reversal of 243123513021 is 120315321342.

243123513021 is a `hidden beast` number, since 2 + 4 + 3 + 1 + 2 + 351 + 302 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2495002500 + 240628510521 = 49950^2 + 490539^2 .

It is not a de Polignac number, because 243123513021 - 2²⁵ = 243089958589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243123513821) 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, 5378076 + ... + 5423093.

It is an arithmetic number, because the mean of its divisors is an integer number (15235050285).

Almost surely, 2^243123513021 is an apocalyptic number.

It is an amenable number.

243123513021 is a deficient number, since it is larger than the sum of its proper divisors (122517693819).

243123513021 is a wasteful number, since it uses less digits than its factorization.

243123513021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10801277 (or 10801274 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 243123513021 its reverse (120315321342), we get a palindrome (363438834363).

The spelling of 243123513021 in words is "two hundred forty-three billion, one hundred twenty-three million, five hundred thirteen thousand, twenty-one".