640766752 has 48 divisors (see below), whose sum is σ = 1325419200. Its totient is φ = 304344832.

The previous prime is 640766741. The next prime is 640766759. The reversal of 640766752 is 257667046.

It is a junction number, because it is equal to n+sod(n) for n = 640766699 and 640766708.

It is not an unprimeable number, because it can be changed into a prime (640766759) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106743 + ... + 112585.

It is an arithmetic number, because the mean of its divisors is an integer number (27612900).

Almost surely, 2^640766752 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 640766752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (662709600).

640766752 is an abundant number, since it is smaller than the sum of its proper divisors (684652448).

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

640766752 is a wasteful number, since it uses less digits than its factorization.

640766752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6025 (or 6017 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 43.

The square root of 640766752 is about 25313.3710121746. The cubic root of 640766752 is about 862.1178880655.

The spelling of 640766752 in words is "six hundred forty million, seven hundred sixty-six thousand, seven hundred fifty-two".