640862804468 has 12 divisors (see below), whose sum is σ = 1122267183492. Its totient is φ = 320215037760.

The previous prime is 640862804467. The next prime is 640862804501. The reversal of 640862804468 is 864408268046.

It can be written as a sum of positive squares in 2 ways, for example, as 270210753124 + 370652051344 = 519818^2 + 608812^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640862804467) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54084455 + ... + 54096302.

It is an arithmetic number, because the mean of its divisors is an integer number (93522265291).

Almost surely, 2^640862804468 is an apocalyptic number.

It is an amenable number.

640862804468 is a deficient number, since it is larger than the sum of its proper divisors (481404379024).

640862804468 is a wasteful number, since it uses less digits than its factorization.

640862804468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108182242 (or 108182240 counting only the distinct ones).

The product of its (nonzero) digits is 14155776, while the sum is 56.

The spelling of 640862804468 in words is "six hundred forty billion, eight hundred sixty-two million, eight hundred four thousand, four hundred sixty-eight".