639464 has 32 divisors (see below), whose sum is σ = 1444800. Its totient is φ = 259200.

The previous prime is 639451. The next prime is 639487. The reversal of 639464 is 464936.

It is a self number, because there is not a number n which added to its sum of digits gives 639464.

It is an unprimeable number.

639464 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 7 ways as a sum of consecutive naturals, for example, 764 + ... + 1364.

It is an arithmetic number, because the mean of its divisors is an integer number (45150).

2⁶³⁹⁴⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (722400).

639464 is an abundant number, since it is smaller than the sum of its proper divisors (805336).

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

639464 is a wasteful number, since it uses less digits than its factorization.

639464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633 (or 629 counting only the distinct ones).

The product of its digits is 15552, while the sum is 32.

The square root of 639464 is about 799.6649298300. The cubic root of 639464 is about 86.1533230280.

The spelling of 639464 in words is "six hundred thirty-nine thousand, four hundred sixty-four".