517985 has 12 divisors (see below), whose sum is σ = 674172. Its totient is φ = 381888.

The previous prime is 517981. The next prime is 517991. The reversal of 517985 is 589715.

517985 = T₁₆ + T₁₇ + ... + T₁₄₅.

It can be written as a sum of positive squares in 6 ways, for example, as 279841 + 238144 = 529^2 + 488^2 .

It is not a de Polignac number, because 517985 - 2² = 517981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (517981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 539 + ... + 1151.

It is an arithmetic number, because the mean of its divisors is an integer number (56181).

2⁵¹⁷⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

517985 is a deficient number, since it is larger than the sum of its proper divisors (156187).

517985 is a wasteful number, since it uses less digits than its factorization.

517985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644 (or 631 counting only the distinct ones).

The product of its digits is 12600, while the sum is 35.

The square root of 517985 is about 719.7117478547. The cubic root of 517985 is about 80.3105119696.

The spelling of 517985 in words is "five hundred seventeen thousand, nine hundred eighty-five".