646917 has 8 divisors (see below), whose sum is σ = 867840. Its totient is φ = 428640.

The previous prime is 646913. The next prime is 646927. The reversal of 646917 is 719646.

It is a happy number.

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

It is not a de Polignac number, because 646917 - 2² = 646913 is a prime.

646917 is a lucky number.

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 646917.

It is not an unprimeable number, because it can be changed into a prime (646913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9 + ... + 1137.

It is an arithmetic number, because the mean of its divisors is an integer number (108480).

2⁶⁴⁶⁹¹⁷ is an apocalyptic number.

It is an amenable number.

646917 is a deficient number, since it is larger than the sum of its proper divisors (220923).

646917 is a wasteful number, since it uses less digits than its factorization.

646917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323.

The product of its digits is 9072, while the sum is 33.

The square root of 646917 is about 804.3115068181. The cubic root of 646917 is about 86.4867388093.

The spelling of 646917 in words is "six hundred forty-six thousand, nine hundred seventeen".