243203240405 has 16 divisors (see below), whose sum is σ = 314841581424. Its totient is φ = 179662679040.

The previous prime is 243203240369. The next prime is 243203240411. The reversal of 243203240405 is 504042302342.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 52429092676 + 190774147729 = 228974^2 + 436777^2 .

It is not a de Polignac number, because 243203240405 - 2⁶ = 243203240341 is a prime.

It is a super-2 number, since 2×243203240405² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 26988086 + ... + 26997095.

It is an arithmetic number, because the mean of its divisors is an integer number (19677598839).

Almost surely, 2^243203240405 is an apocalyptic number.

It is an amenable number.

243203240405 is a deficient number, since it is larger than the sum of its proper divisors (71638341019).

243203240405 is a wasteful number, since it uses less digits than its factorization.

243203240405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53985256.

The product of its (nonzero) digits is 23040, while the sum is 29.

Adding to 243203240405 its reverse (504042302342), we get a palindrome (747245542747).

The spelling of 243203240405 in words is "two hundred forty-three billion, two hundred three million, two hundred forty thousand, four hundred five".