180805518397 has 4 divisors (see below), whose sum is σ = 206634878176. Its totient is φ = 154976158620.

The previous prime is 180805518277. The next prime is 180805518401. The reversal of 180805518397 is 793815508081.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 793815508081 = 157 ⋅5056149733.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-180805518397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (180805510397) 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 3 ways as a sum of consecutive naturals, for example, 12914679879 + ... + 12914679892.

It is an arithmetic number, because the mean of its divisors is an integer number (51658719544).

Almost surely, 2^180805518397 is an apocalyptic number.

It is an amenable number.

180805518397 is a deficient number, since it is larger than the sum of its proper divisors (25829359779).

180805518397 is an equidigital number, since it uses as much as digits as its factorization.

180805518397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25829359778.

The product of its (nonzero) digits is 2419200, while the sum is 55.

The spelling of 180805518397 in words is "one hundred eighty billion, eight hundred five million, five hundred eighteen thousand, three hundred ninety-seven".