518173944649 has 9 divisors (see below), whose sum is σ = 519446141319. Its totient is φ = 516904861440.

The previous prime is 518173944623. The next prime is 518173944667. The reversal of 518173944649 is 946449371815.

The square root of 518173944649 is 719843.

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

It can be written as a sum of positive squares in only one way, i.e., 467728784649 + 50445160000 = 683907^2 + 224600^2 .

It is not a de Polignac number, because 518173944649 - 2²⁵ = 518140390217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (518173944619) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 461418802 + ... + 461419924.

Almost surely, 2^518173944649 is an apocalyptic number.

518173944649 is the 719843-rd square number.

518173944649 is the 359922-nd centered octagonal number.

It is an amenable number.

518173944649 is a deficient number, since it is larger than the sum of its proper divisors (1272196670).

518173944649 is an frugal number, since it uses more digits than its factorization.

518173944649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3528 (or 1764 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 61.

The spelling of 518173944649 in words is "five hundred eighteen billion, one hundred seventy-three million, nine hundred forty-four thousand, six hundred forty-nine".