640259696 has 10 divisors (see below), whose sum is σ = 1240503192. Its totient is φ = 320129840.

The previous prime is 640259657. The next prime is 640259707. The reversal of 640259696 is 696952046.

It is a self number, because there is not a number n which added to its sum of digits gives 640259696.

It is a congruent number.

It is an unprimeable number.

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, 20008100 + ... + 20008131.

Almost surely, 2^640259696 is an apocalyptic number.

It is an amenable number.

640259696 is a deficient number, since it is larger than the sum of its proper divisors (600243496).

640259696 is a wasteful number, since it uses less digits than its factorization.

640259696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40016239 (or 40016233 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 47.

The square root of 640259696 is about 25303.3534536433. The cubic root of 640259696 is about 861.8904223485.

The spelling of 640259696 in words is "six hundred forty million, two hundred fifty-nine thousand, six hundred ninety-six".