491817 has 8 divisors (see below), whose sum is σ = 665280. Its totient is φ = 323120.

The previous prime is 491797. The next prime is 491819. The reversal of 491817 is 718194.

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-491817 is a prime.

It is a super-2 number, since 2×491817² = 483767922978, which contains 22 as substring.

It is a plaindrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 491817.

It is not an unprimeable number, because it can be changed into a prime (491819) 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, 942 + ... + 1367.

It is an arithmetic number, because the mean of its divisors is an integer number (83160).

2⁴⁹¹⁸¹⁷ is an apocalyptic number.

It is an amenable number.

491817 is a deficient number, since it is larger than the sum of its proper divisors (173463).

491817 is a wasteful number, since it uses less digits than its factorization.

491817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2383.

The product of its digits is 2016, while the sum is 30.

The square root of 491817 is about 701.2966562019. The cubic root of 491817 is about 78.9346786855.

The spelling of 491817 in words is "four hundred ninety-one thousand, eight hundred seventeen".