640753267686 has 32 divisors (see below), whose sum is σ = 1541661999360. Its totient is φ = 173436974496.

The previous prime is 640753267673. The next prime is 640753267691. The reversal of 640753267686 is 686762357046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 401473681 + ... + 401475276.

It is an arithmetic number, because the mean of its divisors is an integer number (48176937480).

Almost surely, 2^640753267686 is an apocalyptic number.

640753267686 is an abundant number, since it is smaller than the sum of its proper divisors (900908731674).

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

640753267686 is a wasteful number, since it uses less digits than its factorization.

640753267686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 802948988.

The product of its (nonzero) digits is 60963840, while the sum is 60.

The spelling of 640753267686 in words is "six hundred forty billion, seven hundred fifty-three million, two hundred sixty-seven thousand, six hundred eighty-six".