640276568 has 8 divisors (see below), whose sum is σ = 1200518580. Its totient is φ = 320138280.

The previous prime is 640276561. The next prime is 640276577. The reversal of 640276568 is 865672046.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640276561) 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 as a sum of consecutive naturals, namely, 40017278 + ... + 40017293.

Almost surely, 2^640276568 is an apocalyptic number.

It is an amenable number.

640276568 is a deficient number, since it is larger than the sum of its proper divisors (560242012).

640276568 is a wasteful number, since it uses less digits than its factorization.

640276568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80034577 (or 80034573 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The square root of 640276568 is about 25303.6868459914. The cubic root of 640276568 is about 861.8979930720.

The spelling of 640276568 in words is "six hundred forty million, two hundred seventy-six thousand, five hundred sixty-eight".