640039078 has 24 divisors (see below), whose sum is σ = 1165363632. Its totient is φ = 262375344.

The previous prime is 640039027. The next prime is 640039079. The reversal of 640039078 is 870930046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640039079) 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 in 11 ways as a sum of consecutive naturals, for example, 139725 + ... + 144232.

It is an arithmetic number, because the mean of its divisors is an integer number (48556818).

Almost surely, 2^640039078 is an apocalyptic number.

640039078 is a deficient number, since it is larger than the sum of its proper divisors (525324554).

640039078 is a wasteful number, since it uses less digits than its factorization.

640039078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283996 (or 283989 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 640039078 is about 25298.9936163477. The cubic root of 640039078 is about 861.7914154472.

The spelling of 640039078 in words is "six hundred forty million, thirty-nine thousand, seventy-eight".