640655434360 has 32 divisors (see below), whose sum is σ = 1442205505440. Its totient is φ = 256132257664.

The previous prime is 640655434357. The next prime is 640655434399. The reversal of 640655434360 is 63434556046.

It is a self number, because there is not a number n which added to its sum of digits gives 640655434360.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3979972 + ... + 4137811.

It is an arithmetic number, because the mean of its divisors is an integer number (45068922045).

Almost surely, 2^640655434360 is an apocalyptic number.

It is an amenable number.

640655434360 is an abundant number, since it is smaller than the sum of its proper divisors (801550071080).

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

640655434360 is a wasteful number, since it uses less digits than its factorization.

640655434360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8119767 (or 8119763 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 46.

The spelling of 640655434360 in words is "six hundred forty billion, six hundred fifty-five million, four hundred thirty-four thousand, three hundred sixty".