640275 has 12 divisors (see below), whose sum is σ = 1058712. Its totient is φ = 341440.

The previous prime is 640267. The next prime is 640279. The reversal of 640275 is 572046.

It is a happy number.

It is not a de Polignac number, because 640275 - 2³ = 640267 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640275.

It is not an unprimeable number, because it can be changed into a prime (640279) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4194 + ... + 4343.

It is an arithmetic number, because the mean of its divisors is an integer number (88226).

2⁶⁴⁰²⁷⁵ is an apocalyptic number.

640275 is a deficient number, since it is larger than the sum of its proper divisors (418437).

640275 is a wasteful number, since it uses less digits than its factorization.

640275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8550 (or 8545 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 640275 is about 800.1718565408. The cubic root of 640275 is about 86.1897289492.

The spelling of 640275 in words is "six hundred forty thousand, two hundred seventy-five".