640441376 has 12 divisors (see below), whose sum is σ = 1260869022. Its totient is φ = 320220672.

The previous prime is 640441339. The next prime is 640441393. The reversal of 640441376 is 673144046.

It can be written as a sum of positive squares in only one way, i.e., 544008976 + 96432400 = 23324^2 + 9820^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10006865 + ... + 10006928.

Almost surely, 2^640441376 is an apocalyptic number.

It is an amenable number.

640441376 is a deficient number, since it is larger than the sum of its proper divisors (620427646).

640441376 is a wasteful number, since it uses less digits than its factorization.

640441376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20013803 (or 20013795 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 35.

The square root of 640441376 is about 25306.9432369854. The cubic root of 640441376 is about 861.9719379398.

The spelling of 640441376 in words is "six hundred forty million, four hundred forty-one thousand, three hundred seventy-six".