640832508 has 18 divisors (see below), whose sum is σ = 1619882264. Its totient is φ = 213610824.

The previous prime is 640832497. The next prime is 640832519. The reversal of 640832508 is 805238046.

640832508 is a `hidden beast` number, since 640 + 8 + 3 + 2 + 5 + 0 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (640832497) and next prime (640832519).

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 17800903 = 640832508 / (6 + 4 + 0 + 8 + 3 + 2 + 5 + 0 + 8).

It is a congruent 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, 8900416 + ... + 8900487.

Almost surely, 2^640832508 is an apocalyptic number.

It is an amenable number.

640832508 is an abundant number, since it is smaller than the sum of its proper divisors (979049756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640832508 is a wasteful number, since it uses less digits than its factorization.

640832508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17800913 (or 17800908 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 640832508 is about 25314.6698181114. The cubic root of 640832508 is about 862.1473774674.

The spelling of 640832508 in words is "six hundred forty million, eight hundred thirty-two thousand, five hundred eight".