517661 has 8 divisors (see below), whose sum is σ = 549504. Its totient is φ = 486640.

The previous prime is 517639. The next prime is 517711. The reversal of 517661 is 166715.

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

It is a cyclic number.

It is not a de Polignac number, because 517661 - 2⁶ = 517597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 517661.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 517661.

It is not an unprimeable number, because it can be changed into a prime (517061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1475 + ... + 1791.

It is an arithmetic number, because the mean of its divisors is an integer number (68688).

2⁵¹⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

517661 is a deficient number, since it is larger than the sum of its proper divisors (31843).

517661 is a wasteful number, since it uses less digits than its factorization.

517661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411.

The product of its digits is 1260, while the sum is 26.

The square root of 517661 is about 719.4866225303. The cubic root of 517661 is about 80.2937637156.

The spelling of 517661 in words is "five hundred seventeen thousand, six hundred sixty-one".