640806767999 has 8 divisors (see below), whose sum is σ = 651884509440. Its totient is φ = 629736247000.

The previous prime is 640806767989. The next prime is 640806768001. The reversal of 640806767999 is 999767608046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640806767999 - 2¹² = 640806763903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640806767959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1625927 + ... + 1981224.

It is an arithmetic number, because the mean of its divisors is an integer number (81485563680).

Almost surely, 2^640806767999 is an apocalyptic number.

640806767999 is a deficient number, since it is larger than the sum of its proper divisors (11077741441).

640806767999 is a wasteful number, since it uses less digits than its factorization.

640806767999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3610221.

The product of its (nonzero) digits is 246903552, while the sum is 71.

The spelling of 640806767999 in words is "six hundred forty billion, eight hundred six million, seven hundred sixty-seven thousand, nine hundred ninety-nine".