640266681885 has 16 divisors (see below), whose sum is σ = 1078343885760. Its totient is φ = 323503165440.

The previous prime is 640266681869. The next prime is 640266681889. The reversal of 640266681885 is 588186662046.

It is not a de Polignac number, because 640266681885 - 2⁴ = 640266681869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640266681889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1123274596 + ... + 1123275165.

It is an arithmetic number, because the mean of its divisors is an integer number (67396492860).

Almost surely, 2^640266681885 is an apocalyptic number.

It is an amenable number.

640266681885 is a deficient number, since it is larger than the sum of its proper divisors (438077203875).

640266681885 is a wasteful number, since it uses less digits than its factorization.

640266681885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2246549788.

The product of its (nonzero) digits is 26542080, while the sum is 60.

The spelling of 640266681885 in words is "six hundred forty billion, two hundred sixty-six million, six hundred eighty-one thousand, eight hundred eighty-five".