640861177860507 has 8 divisors (see below), whose sum is σ = 854481698035984. Its totient is φ = 427240721462688.

The previous prime is 640861177860481. The next prime is 640861177860509. The reversal of 640861177860507 is 705068771168046.

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

It is not a de Polignac number, because 640861177860507 - 2⁸ = 640861177860251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640861177860509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17558613 + ... + 39875145.

It is an arithmetic number, because the mean of its divisors is an integer number (106810212254498).

Almost surely, 2^{640861177860507} is an apocalyptic number.

640861177860507 is a deficient number, since it is larger than the sum of its proper divisors (213620520175477).

640861177860507 is a wasteful number, since it uses less digits than its factorization.

640861177860507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31888829.

The product of its (nonzero) digits is 94832640, while the sum is 66.

The spelling of 640861177860507 in words is "six hundred forty trillion, eight hundred sixty-one billion, one hundred seventy-seven million, eight hundred sixty thousand, five hundred seven".