640317 has 8 divisors (see below), whose sum is σ = 868000. Its totient is φ = 419760.

The previous prime is 640307. The next prime is 640333. The reversal of 640317 is 713046.

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

It is not a de Polignac number, because 640317 - 2⁸ = 640061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640293 and 640302.

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 640317.

It is not an unprimeable number, because it can be changed into a prime (640307) 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, 1567 + ... + 1932.

It is an arithmetic number, because the mean of its divisors is an integer number (108500).

2⁶⁴⁰³¹⁷ is an apocalyptic number.

It is an amenable number.

640317 is a deficient number, since it is larger than the sum of its proper divisors (227683).

640317 is a wasteful number, since it uses less digits than its factorization.

640317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 640317 is about 800.1981004726. The cubic root of 640317 is about 86.1916134985.

The spelling of 640317 in words is "six hundred forty thousand, three hundred seventeen".