639960 has 32 divisors (see below), whose sum is σ = 1920240. Its totient is φ = 170624.

The previous prime is 639959. The next prime is 639983. The reversal of 639960 is 69936.

639960 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 15.

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 639960.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2547 + ... + 2786.

2⁶³⁹⁹⁶⁰ is an apocalyptic number.

639960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

639960 is an abundant number, since it is smaller than the sum of its proper divisors (1280280).

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

639960 is a wasteful number, since it uses less digits than its factorization.

639960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5347 (or 5343 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 33.

The square root of 639960 is about 799.9749996094. The cubic root of 639960 is about 86.1755922016.

The spelling of 639960 in words is "six hundred thirty-nine thousand, nine hundred sixty".