640826750 has 16 divisors (see below), whose sum is σ = 1199628144. Its totient is φ = 256330600.

The previous prime is 640826723. The next prime is 640826779. The reversal of 640826750 is 57628046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1281404 + ... + 1281903.

It is an arithmetic number, because the mean of its divisors is an integer number (74976759).

Almost surely, 2^640826750 is an apocalyptic number.

640826750 is a deficient number, since it is larger than the sum of its proper divisors (558801394).

640826750 is a wasteful number, since it uses less digits than its factorization.

640826750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563324 (or 2563314 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 640826750 is about 25314.5560893333. The cubic root of 640826750 is about 862.1447952745.

The spelling of 640826750 in words is "six hundred forty million, eight hundred twenty-six thousand, seven hundred fifty".