640716866832 has 160 divisors (see below), whose sum is σ = 1896320056320. Its totient is φ = 182609809920.

The previous prime is 640716866789. The next prime is 640716866887. The reversal of 640716866832 is 238668617046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 395747719 + ... + 395749337.

It is an arithmetic number, because the mean of its divisors is an integer number (11852000352).

Almost surely, 2^640716866832 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640716866832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (948160028160).

640716866832 is an abundant number, since it is smaller than the sum of its proper divisors (1255603189488).

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

640716866832 is a wasteful number, since it uses less digits than its factorization.

640716866832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3821 (or 3815 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 57.

The spelling of 640716866832 in words is "six hundred forty billion, seven hundred sixteen million, eight hundred sixty-six thousand, eight hundred thirty-two".