640308 has 12 divisors (see below), whose sum is σ = 1494080. Its totient is φ = 213432.

The previous prime is 640307. The next prime is 640333. The reversal of 640308 is 803046.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640308.

It is not an unprimeable number, because it can be changed into a prime (640303) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26668 + ... + 26691.

2⁶⁴⁰³⁰⁸ is an apocalyptic number.

It is an amenable number.

640308 is an abundant number, since it is smaller than the sum of its proper divisors (853772).

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

640308 is a wasteful number, since it uses less digits than its factorization.

640308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53366 (or 53364 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 640308 is about 800.1924768454. The cubic root of 640308 is about 86.1912096735.

The spelling of 640308 in words is "six hundred forty thousand, three hundred eight".