640032 has 48 divisors (see below), whose sum is σ = 1723680. Its totient is φ = 207872.

The previous prime is 640027. The next prime is 640039. The reversal of 640032 is 230046.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×640032² = 819281922048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 639993 and 640020.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640032.

It is not an unprimeable number, because it can be changed into a prime (640039) by changing a digit.

640032 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, 5608 + ... + 5720.

It is an arithmetic number, because the mean of its divisors is an integer number (35910).

2⁶⁴⁰⁰³² 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 640032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (861840).

640032 is an abundant number, since it is smaller than the sum of its proper divisors (1083648).

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

640032 is a wasteful number, since it uses less digits than its factorization.

640032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 640032 is about 800.0199997500. The cubic root of 640032 is about 86.1788238671.

Adding to 640032 its reverse (230046), we get a palindrome (870078).

The spelling of 640032 in words is "six hundred forty thousand, thirty-two".