517987 has 8 divisors (see below), whose sum is σ = 539136. Its totient is φ = 497352.

The previous prime is 517981. The next prime is 517991. The reversal of 517987 is 789715.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-517987 is a prime.

It is a Duffinian number.

517987 is a lucky number.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4788 + ... + 4894.

It is an arithmetic number, because the mean of its divisors is an integer number (67392).

2⁵¹⁷⁹⁸⁷ is an apocalyptic number.

517987 is a deficient number, since it is larger than the sum of its proper divisors (21149).

517987 is a wasteful number, since it uses less digits than its factorization.

517987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257.

The product of its digits is 17640, while the sum is 37.

The square root of 517987 is about 719.7131372985. The cubic root of 517987 is about 80.3106153322.

The spelling of 517987 in words is "five hundred seventeen thousand, nine hundred eighty-seven".