640439752 has 16 divisors (see below), whose sum is σ = 1201213440. Its totient is φ = 320116176.

The previous prime is 640439663. The next prime is 640439753. The reversal of 640439752 is 257934046.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (640439753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17493 + ... + 39835.

It is an arithmetic number, because the mean of its divisors is an integer number (75075840).

Almost surely, 2^640439752 is an apocalyptic number.

It is an amenable number.

640439752 is a deficient number, since it is larger than the sum of its proper divisors (560773688).

640439752 is a wasteful number, since it uses less digits than its factorization.

640439752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25932 (or 25928 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 640439752 is about 25306.9111509090. The cubic root of 640439752 is about 861.9712093570.

The spelling of 640439752 in words is "six hundred forty million, four hundred thirty-nine thousand, seven hundred fifty-two".