640675 has 18 divisors (see below), whose sum is σ = 925908. Its totient is φ = 438480.

The previous prime is 640669. The next prime is 640687. The reversal of 640675 is 576046.

640675 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 640675 - 2³ = 640667 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 964 + ... + 1486.

2⁶⁴⁰⁶⁷⁵ is an apocalyptic number.

640675 is a deficient number, since it is larger than the sum of its proper divisors (285233).

640675 is a wasteful number, since it uses less digits than its factorization.

640675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 640675 is about 800.4217638220. The cubic root of 640675 is about 86.2076736941.

The spelling of 640675 in words is "six hundred forty thousand, six hundred seventy-five".