17808239640361 has 3 divisors (see below), whose sum is σ = 17808243860343. Its totient is φ = 17808235420380.

The previous prime is 17808239640319. The next prime is 17808239640377. The reversal of 17808239640361 is 16304693280871.

The square root of 17808239640361 is 4219981.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1254245444761 + 16553994195600 = 1119931^2 + 4068660^2 .

It is not a de Polignac number, because 17808239640361 - 2³³ = 17799649705769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 17808239640296 and 17808239640305.

It is not an unprimeable number, because it can be changed into a prime (17808239640311) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2109991 + ... + 6329971.

It is an arithmetic number, because the mean of its divisors is an integer number (5936081286781).

Almost surely, 2^{17808239640361} is an apocalyptic number.

17808239640361 is the 4219981-st square number.

17808239640361 is the 2109991-st centered octagonal number.

It is an amenable number.

17808239640361 is a deficient number, since it is larger than the sum of its proper divisors (4219982).

17808239640361 is an frugal number, since it uses more digits than its factorization.

17808239640361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8439962 (or 4219981 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 58.

The spelling of 17808239640361 in words is "seventeen trillion, eight hundred eight billion, two hundred thirty-nine million, six hundred forty thousand, three hundred sixty-one".