640782252 has 96 divisors (see below), whose sum is σ = 1834963200. Its totient is φ = 194147280.

The previous prime is 640782251. The next prime is 640782281. The reversal of 640782252 is 252287046.

640782252 is a `hidden beast` number, since 640 + 7 + 8 + 2 + 2 + 5 + 2 = 666.

640782252 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (640782251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92899 + ... + 99557.

It is an arithmetic number, because the mean of its divisors is an integer number (19114200).

Almost surely, 2^640782252 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 640782252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (917481600).

640782252 is an abundant number, since it is smaller than the sum of its proper divisors (1194180948).

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

640782252 is a wasteful number, since it uses less digits than its factorization.

640782252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6695 (or 6675 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 640782252 is about 25313.6771726274. The cubic root of 640782252 is about 862.1248394871.

The spelling of 640782252 in words is "six hundred forty million, seven hundred eighty-two thousand, two hundred fifty-two".