640345275 has 18 divisors (see below), whose sum is σ = 1146929940. Its totient is φ = 341517360.

The previous prime is 640345253. The next prime is 640345283. The reversal of 640345275 is 572543046.

640345275 is a `hidden beast` number, since 6 + 40 + 345 + 275 = 666.

It is not a de Polignac number, because 640345275 - 2⁸ = 640345019 is a prime.

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, 1422765 + ... + 1423214.

It is an arithmetic number, because the mean of its divisors is an integer number (63718330).

Almost surely, 2^640345275 is an apocalyptic number.

640345275 is a deficient number, since it is larger than the sum of its proper divisors (506584665).

640345275 is a wasteful number, since it uses less digits than its factorization.

640345275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2845995 (or 2845987 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 36.

The square root of 640345275 is about 25305.0444575780. The cubic root of 640345275 is about 861.9288215766.

The spelling of 640345275 in words is "six hundred forty million, three hundred forty-five thousand, two hundred seventy-five".