640608 has 24 divisors (see below), whose sum is σ = 1681848. Its totient is φ = 213504.

The previous prime is 640589. The next prime is 640613. The reversal of 640608 is 806046.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

640608 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3241 + ... + 3432.

It is an arithmetic number, because the mean of its divisors is an integer number (70077).

2⁶⁴⁰⁶⁰⁸ is an apocalyptic number.

It is an amenable number.

640608 is an abundant number, since it is smaller than the sum of its proper divisors (1041240).

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

640608 is a wasteful number, since it uses less digits than its factorization.

640608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6686 (or 6678 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 640608 is about 800.3799097928. The cubic root of 640608 is about 86.2046684702.

The spelling of 640608 in words is "six hundred forty thousand, six hundred eight".