640827528 has 64 divisors (see below), whose sum is σ = 1758957120. Its totient is φ = 192940800.

The previous prime is 640827521. The next prime is 640827553. The reversal of 640827528 is 825728046.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 640827528.

It is not an unprimeable number, because it can be changed into a prime (640827521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33718 + ... + 49178.

It is an arithmetic number, because the mean of its divisors is an integer number (27483705).

Almost surely, 2^640827528 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 640827528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (879478560).

640827528 is an abundant number, since it is smaller than the sum of its proper divisors (1118129592).

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

640827528 is a wasteful number, since it uses less digits than its factorization.

640827528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15638 (or 15634 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The square root of 640827528 is about 25314.5714559816. The cubic root of 640827528 is about 862.1451441719.

The spelling of 640827528 in words is "six hundred forty million, eight hundred twenty-seven thousand, five hundred twenty-eight".