640332 has 108 divisors (see below), whose sum is σ = 2122680. Its totient is φ = 166320.

The previous prime is 640307. The next prime is 640333. The reversal of 640332 is 233046.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a tau number, because it is divible by the number of its divisors (108).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640332.

It is not an unprimeable number, because it can be changed into a prime (640333) by changing a digit.

640332 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 35 ways as a sum of consecutive naturals, for example, 58207 + ... + 58217.

2⁶⁴⁰³³² 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 640332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1061340).

640332 is an abundant number, since it is smaller than the sum of its proper divisors (1482348).

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

640332 is a wasteful number, since it uses less digits than its factorization.

640332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49 (or 23 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 640332 is about 800.2074730968. The cubic root of 640332 is about 86.1922865319.

Multiplying 640332 by its product of nonzero digits (432), we get a square (276623424 = 16632²).

Adding to 640332 its reverse (233046), we get a palindrome (873378).

The spelling of 640332 in words is "six hundred forty thousand, three hundred thirty-two".