640075 has 6 divisors (see below), whose sum is σ = 793724. Its totient is φ = 512040.

The previous prime is 640069. The next prime is 640099. The reversal of 640075 is 570046.

It is not a de Polignac number, because 640075 - 2⁵ = 640043 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12777 + ... + 12826.

2⁶⁴⁰⁰⁷⁵ is an apocalyptic number.

640075 is a deficient number, since it is larger than the sum of its proper divisors (153649).

640075 is a wasteful number, since it uses less digits than its factorization.

640075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25613 (or 25608 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 640075 is about 800.0468736268. The cubic root of 640075 is about 86.1807537740.

Adding to 640075 its reverse (570046), we get a palindrome (1210121).

The spelling of 640075 in words is "six hundred forty thousand, seventy-five".