640017 has 12 divisors (see below), whose sum is σ = 1056640. Its totient is φ = 365688.

The previous prime is 640009. The next prime is 640019. The reversal of 640017 is 710046.

It is not a de Polignac number, because 640017 - 2³ = 640009 is a prime.

It is a Duffinian number.

640017 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5017 + ... + 5142.

2⁶⁴⁰⁰¹⁷ is an apocalyptic number.

It is an amenable number.

640017 is a deficient number, since it is larger than the sum of its proper divisors (416623).

640017 is a wasteful number, since it uses less digits than its factorization.

640017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10172 (or 10169 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 640017 is about 800.0106249294. The cubic root of 640017 is about 86.1781506235.

The spelling of 640017 in words is "six hundred forty thousand, seventeen".