243920417689 has 9 divisors (see below), whose sum is σ = 264133795359. Its totient is φ = 225151382040.

The previous prime is 243920417681. The next prime is 243920417693. The reversal of 243920417689 is 986714029342.

The square root of 243920417689 is 493883.

It is a perfect power (a square), and thus also a powerful number.

243920417689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 36082902025 + 207837515664 = 189955^2 + 455892^2 .

It is not a de Polignac number, because 243920417689 - 2³ = 243920417681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243920417681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6401484 + ... + 6439474.

Almost surely, 2^243920417689 is an apocalyptic number.

243920417689 is the 493883-rd square number.

243920417689 is the 246942-nd centered octagonal number.

It is an amenable number.

243920417689 is a deficient number, since it is larger than the sum of its proper divisors (20213377670).

243920417689 is an frugal number, since it uses more digits than its factorization.

243920417689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76008 (or 38004 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 55.

The spelling of 243920417689 in words is "two hundred forty-three billion, nine hundred twenty million, four hundred seventeen thousand, six hundred eighty-nine".