640065323860 has 12 divisors (see below), whose sum is σ = 1344137180148. Its totient is φ = 256026129536.

The previous prime is 640065323857. The next prime is 640065323869. The reversal of 640065323860 is 68323560046.

It can be written as a sum of positive squares in 2 ways, for example, as 358219008196 + 281846315664 = 598514^2 + 530892^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640065323869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16001633077 + ... + 16001633116.

It is an arithmetic number, because the mean of its divisors is an integer number (112011431679).

Almost surely, 2^640065323860 is an apocalyptic number.

It is an amenable number.

640065323860 is an abundant number, since it is smaller than the sum of its proper divisors (704071856288).

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

640065323860 is a wasteful number, since it uses less digits than its factorization.

640065323860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32003266202 (or 32003266200 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 43.

The spelling of 640065323860 in words is "six hundred forty billion, sixty-five million, three hundred twenty-three thousand, eight hundred sixty".