640886140 has 12 divisors (see below), whose sum is σ = 1345860936. Its totient is φ = 256354448.

The previous prime is 640886087. The next prime is 640886161. The reversal of 640886140 is 41688046.

640886140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 640886140.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16022134 + ... + 16022173.

It is an arithmetic number, because the mean of its divisors is an integer number (112155078).

Almost surely, 2^640886140 is an apocalyptic number.

It is an amenable number.

640886140 is an abundant number, since it is smaller than the sum of its proper divisors (704974796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640886140 is a wasteful number, since it uses less digits than its factorization.

640886140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32044316 (or 32044314 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 640886140 is about 25315.7291026745. The cubic root of 640886140 is about 862.1714281606.

The spelling of 640886140 in words is "six hundred forty million, eight hundred eighty-six thousand, one hundred forty".