640817658795 has 32 divisors (see below), whose sum is σ = 1060715041344. Its totient is φ = 330132224000.

The previous prime is 640817658791. The next prime is 640817658839. The reversal of 640817658795 is 597856718046.

It is a happy number.

It is not a de Polignac number, because 640817658795 - 2² = 640817658791 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640817658791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5096202 + ... + 5220431.

It is an arithmetic number, because the mean of its divisors is an integer number (33147345042).

Almost surely, 2^640817658795 is an apocalyptic number.

640817658795 is a deficient number, since it is larger than the sum of its proper divisors (419897382549).

640817658795 is a wasteful number, since it uses less digits than its factorization.

640817658795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10316783.

The product of its (nonzero) digits is 101606400, while the sum is 66.

The spelling of 640817658795 in words is "six hundred forty billion, eight hundred seventeen million, six hundred fifty-eight thousand, seven hundred ninety-five".