640332528 has 320 divisors, whose sum is σ = 2057011200. Its totient is φ = 169344000.

The previous prime is 640332521. The next prime is 640332529. The reversal of 640332528 is 825233046.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640332521) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9018733 + ... + 9018803.

It is an arithmetic number, because the mean of its divisors is an integer number (6428160).

Almost surely, 2^640332528 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 640332528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1028505600).

640332528 is an abundant number, since it is smaller than the sum of its proper divisors (1416678672).

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

640332528 is a wasteful number, since it uses less digits than its factorization.

640332528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 640332528 is about 25304.7925895471. The cubic root of 640332528 is about 861.9231022249.

The spelling of 640332528 in words is "six hundred forty million, three hundred thirty-two thousand, five hundred twenty-eight".